Israel sealed off the West Bank yesterday amid tension with key ally the United States and in Jerusalem over plans to build new homes for Jewish settlers and fears of fresh violence at Al-Aqsa mosque compound.
US Secretary of State Hillary Clinton rebuked Israeli Prime Minister Benjamin Netanyahu, calling the new settlements announcement "a deeply negative signal" about Israel's approach to US ties.
The 48-hour closure to run until midnight on Saturday drew harsh criticism from European Parliament chief Jerzy Buzek who said it was "unhelpful" and would complicate efforts to revive peace talks.
Israeli police also barred men under the age of 50 from praying at the site of the mosque compound, which is holy to both Muslims and Jews.
Isolated incidents broke out after the noon prayers. Four Palestinians were arrested after youths threw stones near Jerusalem's Old City, police said.
Security forces used stun grenades to disperse the protesters, one of whom threw a brick that smashed the windscreen of a car in which a family of settlers was travelling. Two policemen were slightly injured.
Defence Minister Ehud Barak ordered the army to seal off the Israeli-occupied West Bank for security reasons, an army spokesman said.
The move came as US Vice President Joe Biden was due to leave the region after visits to Israel and the West Bank to promote renewed peace talks - a mission marred by Israel's announcement to build 1,600 new settler homes in predominantly Arab east Jerusalem.
The plan infuriated the US and cast doubts over the outlook for the indirect talks which the Palestinians had reluctantly agreed to hold after a 14-month hiatus in negotiations.
Mrs Clinton had harsh words for Mr Netanyahu, saying in an early morning phone call yesterday that Israel's "action had undermined trust and confidence in the peace process and in America's interest".
She told Mr Netanyahu "she could not understand how this happened particularly in light of the US strong interest in Israel's security", State Department spokesman Philip Crowley said.
And she made clear that "the Israeli government needed to demonstrate not just in words, but through specific actions, that they are committed to this relationship and to the peace process".
Mr Buzek said the West Bank closure would harm efforts to renew the peace talks and urged Israel to reconsider its "unhelpful" decision.
"Today we need every sign of good will for further peace negotiations to reconvene as soon as possible," he said during a visit to Jordan to attend the plenary of the Euro-Mediterranean Parliamentary Assembly.
US Middle East envoy George Mitchell on Thursday called Palestinian President Mahmud Abbas to press him to go ahead with the planned talks, a Palestinian official said.
But Mr Abbas, who is visiting Tunisia, demanded US guarantees that Israel first freeze the project to build new homes in the Ramat Shlomo settlement.
He told US officials that "it is very difficult for us to go to any negotiations, direct or indirect, without the cancellation of the Israeli building project," Palestinian negotiator Saeb Erakat said yesterday.
He quoted Mr Abbas as saying any peace talks had been "compromised by recent Israeli actions".
The US State Department insisted on Thursday it had not heard anything to indicate the Palestinians had pulled out of the planned talks and said that Mr Mitchell was due back in the region next week.
Mr Netanyahu on Thursday apologised for the timing of the settlement announcement, made as Mr Biden was holding a day of talks in Jerusalem on Tuesday.