Putin vows 'revenge': Russians mourn dozens of victims

Armed attack in Russia incites panic, prompts security increase. President vows revenge; four suspects arrested. Afghanistan's ISIL affiliate claims responsibility. The attack occurred in a crowded market in a major city, leaving dozens dead and many injured. Subscribe to our channel http://bit.ly/AJSubscribe Follow us on Twitter https://twitter.com/AJEnglish Find us on Facebook https://www.facebook.com/aljazeera Check our website: https://www.aljazeera.com/ Check out our Instagram page: https://www.instagram.com/aljazeeraenglish/ Download AJE Mobile App: https://aje.io/AJEMobile #PutinRevenge #RussianMourn #VictimsVowed #Putin #Revenge #RussianVictims #Mourn #Vowed