Ramallah - Palestinian President Mahmoud Abbas ordered all celebrations for the New Year and for next week's Greek Orthodox Christmas Day in Bethlehem cancelled Tuesday.

The celebrations were called off as a result of a massive Israeli offensive in the Gaza Strip that had left over 380 Palestinians dead and more than 1,800 wounded.

A statement issued by Abbas' office said his Fatah movement had also cancelled celebrations marking 44 years since its inception. Fatah celebrates its creation every January 1.

New York - UN Secretary General Ban Ki-moon held Tuesday telephone conversations with other members of the quartet - the diplomatic mediating group on the Middle East peace process - on the situation in Gaza Strip, a UN spokeswoman said.

Ban talked to US Secretary of State Condoleezza Rice, Russian Foreign Minister Sergey Lavrov and European Union's chief foreign affairs Javier Solana. He also talked to French Foreign Minister Bernard Kouchner and the quartet's envoy to the Middle East, former British Prime Minister Tony Blair.

Washington - US President George W Bush spoke with Palestinian President Mahmoud Abbas on Tuesday over efforts to achieve "a sustainable ceasefire" to end the fighting in the Gaza Strip, the White House said.

Bush also spoke with Palestinian Prime Minister Salam Fayyad and Egyptian President Hosny Mubarak, said Gordon Johndroe, a White House spokesman.

"They agreed that for any ceasefire to be effective, it must be respected, particularly by Hamas," Johndroe said in Crawford, Texas, where Bush is vacationing.

Egyptian security forces on Tuesday arrested 23 members of the banned opposition Muslim Brotherhood group as they prepared to meet to discuss the situation in the Gaza Strip, according to a security source.

The source said the 23 were arrested in front of Egypt's Doctors Syndicate, where the meeting to discuss the Israel's attacks on the Gaza Strip was due to take place.

Earlier on Tuesday, dozens of security elements were seen surrounding the syndicate, located in downtown Cairo.

European Union foreign ministers began Tuesday evening an emergency session to discuss the escalating conflict in the Gaza Strip.

Reports ahead of the meeting said the ministers would, among others, examine the chances for setting up a "humanitarian ceasefire" amid the rising casualty figures and ongoing attacks.

France, on its next-to-last day in its six-month term as EU president, had called the meeting after talks between French President Nicolas Sarkozy and Egyptian President Hosny Mubarak.

Tel Aviv  - Israeli Prime Minister Ehud Olmert rejected a reported French proposal to observe a 48-hour truce in Gaza, with a spokesman saying Tuesday the caretaker premier believes such a move would be a "mistake."

An Israeli defence official, earlier told Deutsche Presse-Agentur dpa that Israeli Defence Minister Ehud Barak had received a proposal from French Foreign Minister Bernard Kouchner to unilaterally end its assault on Gaza for 48 hours, allowing Hamas to suspend its rocket and mortar attacks as well.