The European Commission on Thursday suspended its humanitarian aid projects in the Gaza Strip, citing the escalating sectarian violence.

"I fervently hope that the projects can resume very soon," said EU Humanitarian Aid Commissioner Louis Michel.

EU humanitarian operations in both Gaza and the West Bank totaled $110 million last year. So far this year, it has earmarked euro60 million $80 million.

On Thursday, violence continued unabated, with Hamas fighters overrunning one of the rival Fatah movement's most important security installations in the Gaza Strip on Thursday, and witnesses said the victors dragged vanquished gunmen from the building and executed them in the street.

Some 80 people, most of them militants, have been killed since a spike in violence Sunday sent Gaza into civil war. At least 15 people died on Thursday.

"This is a time when people desperately need protection and support. The warring parties must respect the principles of international humanitarian law," said Michel.

Meanwhile, the Rafah border crossing between Egypt and the Gaza Strip, monitored by an EU mission since November 2005, has been closed since June 9 due to security concerns, an official said.

"I can't tell you when the border will next be open. Since 2005 we have been open only 20 percent of the time," Maria Telleria, spokeswoman for the EU mission, said in a telephone interview.

"The situation is quite difficult. At this moment we're on standby," she said.

The mission monitors, verifies and evaluates the Palestinian Authority's border guards at the Rafah passenger terminal, which opened after Israel's 2005 pullout from Gaza to reassure an apprehensive Israel that Palestinian inspectors would prevent the smuggling of weapons and militants.

Results, however, have been mixed, amid frequent closings forced by Israel due to security concerns. Although the Palestinians run the crossing, Israel still has final say over whether it operates.

Telleria said the EU mission has been under pressure in the last year from Israel.

Despite the escalating violence, EU External Relations Commissioner Benita Ferrero-Waldner called on the Palestinians to stick with a national unity government.

"Now is not the time to give up on national unity, both in the government and in the security sector," she said. "I call on both Hamas and Fatah to invest all their energy in this coalition."

European officials urge calm in Gaza

British Foreign Secretary Margaret Beckett on Wednesday denounced fighting between the rival Palestinian factions as "senseless," and said Britain was continuing to press for the release of BBC correspondent Alan Johnston, abducted in Gaza City three months ago.

In a statement released late Wednesday, Beckett called the fighting a "tragedy" and said she would be speaking to Palestinian Authority Mahmoud Abbas, as well as the governments in Egypt and Saudi Arabia, to explore ways to resolve the crisis.

"This fighting is a tragedy. It puts civilians at risk... It makes it harder for the international community to extend assistance to the people," she said.

Beckett said she would appeal to Abbas to ensure that "cool heads prevail" in the conflict.

German Chancellor Angela Merkel called Thursday for the warring factions to end their conflict.

"The events of the last days have really effected us," Merkel told the German Parliament and said that Hamas and Fatah needed to end their violence immediately.

Merkel spoke by telephone to both Prime Minister Ehud Olmert and the Abbas on Wednesday evening.

In her telephone call with Abbas, Merkel gave her support to the efforts aimed at stabilizing the situation in Gaza, said German government spokesmen Ulrich William in Berlin.