Israel says it is closing border crossings to the West Bank during the celebration of Rosh Hashanah, the Jewish New Year festival.

Officials said the closure will last from early Monday to late Wednesday. Such closures are routine during Jewish holidays. Israel says they are necessary to prevent attacks by Palestinian militants. Exceptions are made for medical patients and other humanitarian needs.

Sunday, outgoing Israeli Prime Minister Ehud Olmert said extremism is threatening democracy in the country, after a pipe bomb attack wounded a critic of Israel's settler movement.

In his weekly Cabinet meeting, Mr. Olmert said Thursday's pipe bomb attack outside the home of Israeli scholar Ze'ev Sternhell appears to have been carried out by a new right-wing Israeli underground organization. He said authorities are working quickly to arrest those involved.

In other violence, Israeli police said a Palestinian shepherd was found shot to death in the West Bank Sunday. Palestinians are accusing Jewish settlers of killing him.

An Israeli police spokesman says the youth's body has been taken for an autopsy and that police are investigating.

Other shepherds said they saw a white car belonging to settlers pursue the teen late Saturday, and then heard gunshots.

Tensions between Jewish settlers and Palestinians in the West Bank have been running high in recent weeks.

Some information for this report was provided by AFP and AP.