Israel warns of action on Gaza as fighting rages

GAZA, May 18 (Reuters) Palestinian rival factions fought each other in Gaza today and Israeli aircraft killed a Hamas fighter as Israel threatened to take ''vibrant measures'' to stop rocket attacks on its territory.

Palestinian President Mahmoud Abbas, whose Fatah faction has been accused by Hamas of joining forces with Israel against it, called US Secretary of State Condoleezza Rice to ask her to halt an Israeli ''military escalation'', a Palestinian news agency said.

Fatah and Hamas forces, locked in a week-old round of fighting, waged a fierce battle in Gaza City in which witnesses said three rocket-propelled grenades were fired at the pro-Hamas Islamic University campus.

In Tel Aviv, Israeli Foreign Minister Tzipi Livni told foreign ambassadors the government may decide further action within days and noted the cabinet would meet as usual on Sunday.

''We will see sustained and vibrant measures to end the attacks to end the rocket attacks and remove the threat to southern Israel,'' government spokesman David Baker said.

Israeli forces have recently completed training for a possible ground offensive in the Gaza Strip, from which they and Israeli settlers withdrew in 2005.

Tanks and some other troops took up positions on Thursday, just inside the crowded coastal enclave in a move the military called ''defensive''.

At least nine Hamas fighters have been killed in Israeli strikes since yesterday morning. Militants from Gaza have fired about 100 rockets at the town of Sderot and its surroundings in the past week, causing several injuries but no deaths.

''For too long the international community took this situation in the southern part of Israel as acceptable, as part of life in Israel, and it's not. Enough is enough,'' Livni said, citing a need to put pressure ''on these terrorists''.

Abbas, whose Fatah faction formed a unity government with Hamas in March, was quoted by Wafa news agency as asking Rice ''to stop the Israeli military escalation against our people and continue their efforts to push the peace process forward''.

The Palestinian Authority has been crippled since Hamas, which refuses to recognise Israel, won parliamentary elections early last year, prompting Israeli and international sanctions.

UNIVERSITY BATTLE Heavy gunfire reverberated around the Islamic University in Gaza City, heart of the densely packed coastal enclave that is home to some 1.5 million people. Hamas officials said Abbas's Presidential Guard, a force now receiving training and funding from the United States, was firing grenades at Hamas fighters.

A spokesman for the Guard denied that and accused Hamas of using the university as a fire base for attacks on nearby police stations. ''We should unite against the occupation,'' he added.

A ceasefire agreed 36 hours earlier had not held. Nearly 50 people have died in factional fighting in the past week.

Referring to a handful of Israeli air strikes on Hamas targets yesterday, Hamas movement spokesman Fawzi Barhum said: ''Israeli ocupation forces are bombarding Hamas headquarters and the Presidential Guard is bombarding the Islamic University.

''We wonder where the Presidential Guard get their orders.'' A Palestinian hospital official said at least one man was killed and others were wounded when Israeli helicopter gunships fired on them after they launched a rocket into Israel.

The Israeli military said it attacked the rocket crew in the northern Gaza Strip and that eight improvised Qassam missiles had struck Israel today morning alone. One hit a house in the town of Sderot. Medics said there were only minor injuries.

In the early hours, four Hamas fighters were killed when their base near the Gaza Strip's eastern border with Israel was hit by what local officials said appeared to be at least one missile from an F-16 jet.

REUTERS SYU KP1548