A huge search operation is underway in Iran after a helicopter carrying the country’s President Ebrahim Raisi crashed in the mountainous north-west of the country in heavy fog. Iran’s Foreign Minister Hossein Amirabdollahian was also on the aircraft. The men had been visiting Iran’s remote mountain border region with Azerbaijan to inaugurate a new dam project. Two other helicopters in the convoy made the journey safely. Rescue teams are attempting to locate the helicopter but are being hampered by very poor weather. Iran’s army is reported to have ordered that all resources needed be sent to the search area. The Red Crescent is helping with the search operation. Drones and rescue dogs are being used in the attempt to locate the helicopter. Countries in the region including Turkey have offered assistance with the search. Mass prayers are being said in mosques in Iran. Iran’s state-run television first announced news of what they described as a “hard-landing”. The country’s supreme leader Ayatollah Ali Khamenei delivered a message of calm, saying he hoped that God would return the President to the people. He told Iranians that there would be no disruption to the running of the country. President Raisi has been a key and controversial figure in Iran for many decades, regarded as a hardliner within the Islamic Republic’s leadership. The accident comes at a time of high tension in the Middle East, with the war in Gaza and fears that the conflict could widen. Israel and the United States have accused Iran of backing militant groups including Hamas in Gaza, Hezbollah in Lebanon and the Houthis in Yemen. Recently Iran fired hundreds of missiles at Israel. An airstrike on a military base in Iran was widely seen as Israel's response to that attack. Foreign Minister Hossein Amirabdollahian is a well-known figure on the international stage, where he has been involved in talks and negotiations about Iran's nuclear programme. Jane Hill presents BBC News at Ten reporting by Caroline Hawley. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #BBCNews

Robots have integrated in our lives in different ways and have taken over some tasks which were exclusively done by humans. But, robots have not yet been able to have a sense of touch - could this be about to change? This video is from BBC Click, the BBC’s flagship technology programme. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #Robots #Technology #BBCNews

A helicopter in a convoy carrying the Iranian president has been involved in an accident, state media is reporting. It is currently unclear whether Iranian President Ebrahim Raisi was on board the helicopter that state media say experienced a hard landing. The Interior Minister said rescuers were still trying to reach the site due to the difficult weather conditions. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #Iran #BBCNews

Many cancer treatments can be harsh on patients and not all are successful despite huge progress made by researchers and scientists. However, technology like Artificial Intelligence (AI) and robotics are now helping to discover more effective drugs which have fewer side-effects. This video is from BBC Click, the BBC’s flagship technology programme. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #Cancer #AI #BBCNews

Further bad weather is hampering rescue efforts in southern Brazil, where flooding has left vast areas underwater. In the three weeks since the storms first hit the state of Rio Grande do Sul, at least 150 people have died, and 600,000 have been forced to leave their homes. With many roads underwater or flooded, rescue flights are currently the only way of delivering food and aid to people still trapped and of transporting people to hospital – but it's not without its risks. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #Brazil #Flooding #BBCNews

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Ukrainian boxer, Oleksandr Usyk, has become the first undisputed world heavyweight champion in 25 years. He beat Britain's Tyson Fury in a fiercely competitive contest in the Saudi capital, Riyadh, which went the entire twelve rounds. Usyk, 37, won on a split decision, which meant Fury, 35, lost for the first time in his 16-year professional career. The heavyweight world title is considered by boxing lovers as the greatest, most coveted, prize in sport. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #OleksandrUsyk #TysonFury #BBCNews

Warning: This film includes descriptions some viewers may find distressing. In South Korea, K-pop stars have fame, fortune and millions of female fans. But, some led a double life. This film tells the story of the female journalists who took on the task of investigating the secret chat groups where evidence of sexual crimes were being shared by prominent K-pop stars. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #KPop #SouthKorea #BBCNews

Plastic is one of the most incredible materials in the modern world - but the way we use it damages the environment. What’s the solution? Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news Video made in partnership with @bbcideas and The Open University. #PlasticPollution #BBCIdeas #BBCNews

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Russia’s President Putin has said there are no plans to capture the country's second city Kharkiv, after Russian troops crossed the border into north eastern Ukraine. The Russian leader said his forces were advancing in order to protect the Russian border region. Ukraine’s President Volodymyr Zelensky has admitted that there were issues with military staffing and morale, saying a number of existing brigades were empty. He said the country's air fleet was lacking and renewed calls for allies to send more air defence and fighter jets. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #Ukraine #Russia #BBCNews

CCTV has emerged appearing to show rap mogul Sean "Diddy" Combs attacking singer Casandra "Cassie" Ventura in a hotel hallway in 2016. The video, aired by CNN, has surfaced in the wake of allegations by Ms Ventura about her ex-boyfriend and producer in a lawsuit last year. She has not commented, but her lawyer said it confirms "the disturbing and predatory behaviour of Mr Combs". A lawyer for Mr Combs has not responded to a BBC request for comment. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #BBCNews

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Ukraine’s President Volodymyr Zelensky has admitted that a lack of military manpower is sapping its forces' morale. He was speaking as new laws to boost army recruitment come into effect. Prisoners will now be allowed to join, and fines have gone up for men who ignore the order to fight. Ukraine’s forces are short on weapons and are trying to shore up a weakened front line. They are facing growing military pressure from Russia, which has made its largest territorial gains in the country in 18 months. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #BBCNews

Israeli forces have recovered the bodies of three hostages from Gaza, the Israel Defense Forces (IDF) say. The bodies were those of Shani Louk, Amit Buskila, and Itzhak Gelerenter, it said. The IDF said they had been murdered on 7 October and their remains taken back to Gaza. Local media reported that the bodies were found in a Hamas tunnel. About 1,200 people were killed in an unprecedented attack when Hamas gunmen burst into Israel - they took 252 others back to Gaza as hostages. After the 7 October attacks, Israel launched an offensive in Gaza that has killed more than 35,000 people, mostly civilians, according to the Hamas-run health ministry. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #Israel #Gaza #BBCNews

In 1961, the Cuban revolutionary leader Fidel Castro talked to the BBC about his land reform – passed this week in 1959 – and how he wanted peace. But it was the start of a spiralling situation between the US and Cuba that would push the world to the brink of catastrophe. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #US #Cuba #BBCNews

Taiwan will enter a new era on Monday, as President Tsai ying-Wen hands over power. She's served two terms in office. And in that time, she has faced growing pressure from Beijing, which sees the self-governing island as a breakaway province. The Chinese President, Xi Jinping, has said that what he calls 'reunification' must be fulfilled, and Taiwan has effectively become more dependent on support from the US to ensure it continues to self-govern. Our correspondent Rupert Wingfield-Hayes has been to meet President Tsai, and ask her about her legacy. Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #Taiwan #BBCNews

Scientists believe they may have solved the mystery of how 31 pyramids, including the world-famous Giza complex, were built in Egypt more than 4,000 years ago. A research team from the University of North Carolina Wilmington has discovered that the pyramids are likely to have been built along a long-lost, ancient branch of the River Nile - which is now hidden. For many years, archaeologists have thought that ancient Egyptians must have used a nearby waterway to transport materials such as the stone blocks needed to build the pyramids on the river. But up until now, "nobody was certain of the location, the shape, the size or proximity of this mega waterway to the actual pyramids site". Subscribe here: http://bit.ly/1rbfUog For more news, analysis and features visit: www.bbc.com/news #AncientEgypt #Pyramids #BBCNews