Militants of the Al-Aqsa Martyrs Brigades, the armed wing of the Fatah movement, vowed Monday to avenge the death of a Palestinian prisoner they say was tortured in an Israeli jail.

"This horrific crime will not go unpunished and we promise the Zionist occupation that we will respond to this crime," said a statement distributed to crowds at the funeral of Arafat Jaradat, while armed and masked members of the militant group watched from rooftops, AFP journalists at the scene reported.