Palestinian president Mahmud Abbas on Friday condemned the torching by Palestinians of a West Bank site holy to Jews amid warnings it could inflame more than two weeks of deadly violence.

Abbas called the arson attack on the flashpoint Joseph's Tomb in Nablus irresponsible and said a committee was being formed to investigate. The overnight fire was started with molotov cocktails.

Many Jews believe the tomb to be the final resting place of the Old Testament patriarch.