GAZA CITY, 29 September — Thousands of Palestinians held street protests in the Gaza Strip yesterday to mark the second anniversary of their intifada (uprising) against the harsh Israeli occupation, pledging to continue the uprising and support their besieged leader, Yasser Arafat.

Although he endured his ninth day under siege in his Ramallah office, President Arafat was boosted by demonstrations of popular support mainly in Gaza, while Washington was turning up the heat on Israel for an end to the standoff.

A defiant Arafat addressed by telephone a crowd of 20,000 Palestinians in Gaza City, urging them to continue their struggle against Israeli occupation despite the 2,500 lives it has already claimed. “We want to defend our holy places, both Christian and Muslim, to defend Jerusalem and every centimeter of our land... We will be the winners, the victory will be ours,” Arafat said.

Among the sea of Palestinian flags, many demonstrators also waved Arafat’s keffiyah — or Palestinian headdress — and posters of their beleaguered leader, chanting: “We will support our president from siege to siege.”

Arafat’s mainstream Fatah movement issued a statement yesterday, calling on the Palestinian people to continue its uprising. “This nation knows only one language: self-defense and no surrender.”

The colors of radical groups were also much in evidence, as the Al-Aqsa Martyrs Brigades, an armed offshoot of Arafat’s Fatah, promised the Gaza crowd over loudspeakers to step up its attacks against Israel.

Hamas spiritual leader Sheikh Ahmad Yassin vowed there would be no letup in the intifada. “The martyrdom operations (suicide bombings) and the mortar operations will continue and will escalate because this is the only weapons we have and this enemy understands only the language of force,” he told reporters.

The protests came amid high tension in the Gaza Strip, where two more Palestinians were killed yesterday. A teenager was killed when a group of Palestinian youth was attacked by the heavily-armed Israeli soldiers near the Jewish settlement of Netzarim, Palestinian security sources said. Fifteen youngsters were wounded in similar attacks elsewhere.

Thousands of Palestinians took to the streets in refugee camps across Lebanon yesterday vowing to continue the uprising. About 5,000 protesters marched in the southern Ain El-Hilweh refugee camp, Lebanon’s largest, carrying pictures of Arafat and praising him as their steadfast leader.

Earlier, a local leader of the Al-Aqsa Martyrs Brigades was killed when bullets struck his home in the southern Gaza Strip as Israeli troops fired on buildings in the area, witnesses said. His funeral in Rafah was attended by 3,000 people who called for revenge.

Sparking more fears of violence, the armed wing of the Hamas movement vowed “painful revenge” for an Israeli assassination attempt against their Gaza Strip leader, Mohammad Deif, who survived a missile attack on Thursday that killed two of his fellow activists.

Extra security forces were deployed in Israel’s main cities, in malls and bus stations, while checkpoints along the Green Line separating Israel from the West Bank were beefed up. Seven Palestinians were arrested by the Israeli Army in the West Bank, three of them in the northern city of Nablus, an Israeli military source said, without giving further information.

Arafat was still trapped with his 250-strong entourage in his crumbling Ramallah office as the cycle of Israeli-Palestinian violence entered its third year. Top Palestinian negotiator Saeb Erekat even told an Egyptian newspaper published yesterday Sharon could soon kill Arafat.

But Arafat has shown no sign of backing down and, following a series of rare rebukes by its chief US ally over deadly military operations, Israel was coming under increasing pressure to end the crisis.