The United States, the European Union (EU) and Russia have called on the Palestinians and Israel to remain calm and exert restraint following the Israeli raid of aJericho prison, an event Palestinian President Mahmoud Abbas termed as "an unforgivable crime."

Israeli troops raided the prison on Tuesday and arrested prominent Palestinian militants jailed there, including Ahmed Saadat, leader of the Popular Front for the Liberation of Palestine (PFLP).

The move triggered a furious response by the Palestinians across the West Bank and Gaza Strip.

As retaliatory actions went on, the United States on Wednesday urged all parties in the Middle East to remain "calm and restraint."

"We are continuing to stay in contact with the parties in the region. We continue to urge calm and restraint," White House spokesman Scott McClellan said.

The EU also called for an end to attacks. While urging the Palestinian National Authority (PNA) to restore order, EU External Relations Commissioner Benita Ferrero-Waldner also condemned Israel's move and said its treatment of prison guards and inmates was "unacceptable."

Also on Wednesday, Russian Foreign Minister Sergei Lavrov called on the Israelis and Palestinians to exercise restraint in a phone conversation with U.S. Secretary of State Condoleezza Rice.

Saadat, seized by Israeli troops during the Tuesday attack, hasbeen jailed for almost four years for an alleged role in the murder of Israeli Tourism Minister Rehavam Zeevi in 2001.

According to an agreement reached between the PNA and Israel four years ago, the people held in the Jericho jail are not seen as prisoners but reserved people under supervision of unarmed American and British monitors.

Israel has explained that the Tuesday raid came after Abbas said earlier that he would release Saadat.

The Palestinian president has strongly condemned the Israeli attack. "Israeli raid on the prison is an abduction of imprisoned Palestinians and an unforgivable crime," he said during a tour of the destroyed jail.

The Islamic Resistance Movement (Hamas) and the PFLP have also condemned the raid and promised retaliation.

Hours after the operation in Jericho began, gunmen kidnapped about nine foreigners in the Gaza Strip and attacked British Council offices in the West Bank city of Ramallah.

However, reports on Wednesday said the nine foreigners-- two Australians, one American, four French nationals, one Swiss and one Korean -- had all been released.

The Palestinian authorities also said Wednesday that the Rafah crossing on Gaza-Egypt border, which was closed down Tuesday afternoon amid retaliation attacks, had been reopened.

But other crossings between the Gaza Strip and Israel remained closed.