The long-delayed funeral for Hezbollah’s leader Hassan Nasrallah is taking place Sunday, nearly five months after he was killed in a massive Israeli airstrike on the southern suburbs of Beirut.

BEIRUT—As hundreds of thousands of people gathered for the funeral of slain Hezbollah leader Hassan Nasrallah in Beirut on Sunday, its current chief vowed to continue fighting Israel as the group projected its power despite an Israeli offensive that has left it weakened and in disarray.

Large numbers of Hezbollah followers flocked to Beirut's largest sports stadium on Sunday to attend a mass funeral of their slain leader Seyyed Hassan Nasrallah, nearly five months after he was assassinated.