Two Jewish settlers were wounded today in a blast near the settlement of Oranit in the northern West Bank, Israeli military sources said.
This comes after it was reported that Israelis and Palestinians were observing a truce. Both sides had pulled back their forces at the urging of the United States.
During the night there had been several skirmishes in the West Bank and Gaza Strip.
The Israeli army claimed in all cases Palestinians opened fire, and that in all but two, Israeli troops responded.
The Palestinian leader has ordered his forces to prevent attacks on Israelis, and to show restraint even if fired on.
Israel responded by withdrawing tanks from Palestinian territory and promising to halt military strikes.
Mr Arafat has left Gaza to brief the leaders of Egypt, Jordan and possibly Saudi Arabia on the ceasefire efforts, his office says.
In Washington, President Bush has praised Mr Arafat's truce announcement, saying it is a "glimmer of hope".
PA