Israel defied a U.N. Security Council demand Tuesday to end its six-day siege of Yasser Arafat's devastated West Bank headquarters, and nine Palestinians were killed in an Israeli strike against alleged munitions factories and other targets in Gaza City.

Israel's siege drew criticism from President Bush and many Israelis who questioned the wisdom of a military operation that may have boosted the Palestinian leader's popularity at a time when voices had begun to be heard urging him to share power.

Sporadic pro-Arafat demonstrations persisted Tuesday despite curfews imposed in the West Bank in an effort to halt homicide attacks.

With the United States abstaining, the Security Council demanded early Tuesday that Israel end its operations, "including the destruction of Palestinian civilian and security infrastructure." The resolution also called on the Palestinian Authority to ensure "those responsible for terrorist acts are brought to justice."

In Washington, Bush said: "We've got to end the suffering. I thought the actions the Israelis took were not helpful in terms of the establishment and development of the institutions necessary for a Palestinian state to emerge."

Unmoved, Israeli Defense Minister Binyamin Ben-Eliezer said that "no resolution, and no person, can take from us our exclusive right to defend our homes, our people."

Cabinet Secretary Gideon Saar said the siege would continue until some 200 people inside the compound give up, asserting many are terrorists who must be put on trial. Apparently hinting at possible use of force, he added: "I'm not convinced it will end in them being given up -- but it must end with their capture."

Palestinians took heart from the U.N. resolution. Arafat released a statement praising it, and Cabinet Minister Saeb Erekat said it should be enforced, "because Israel is the champion of nations undermining Security Council resolutions and not implementing" them.

Telephone lines to Arafat's building were cut Tuesday, Palestinians said, leaving Arafat and his aides with only cellular phones to communicate with the outside world. Israel's army denied any knowledge of the cut lines.

Israeli soldiers, tightly ringing Arafat's building with tanks, didn't allow visitors inside, but the military eased restrictions for reporters in the rest of Ramallah, letting them enter and leave town.

Only two weeks ago, Arafat absorbed his worst-ever internal setback when the Palestinian legislature forced his Cabinet to resign, reflecting growing popular discontent with government mismanagement and the handling of the two years of violence with Israel.

Before Thursday -- when Israeli tanks attacked Arafat's compound in response to two Palestinian homicide bombings that left the bombers and seven other people dead -- Palestinians were openly discussing limiting Arafat's powers.

Now, the mood may have shifted. Masked gunmen opened fire Tuesday at the house of Nabil Amr, Palestinian security officials said. No one was hurt. Amr is a former Arafat aide turned critic who is a leading voice calling for a prime minister to take over some of Arafat's duties.

Earlier Tuesday, dozens of Israeli tanks moved deep into Gaza City, exchanging fire with Palestinian gunmen and killing nine people, including six civilians.

The Israeli military said its forces blew up 13 weapons workshops and the house of a Hamas militant who killed five Israeli teenagers in a shooting rampage in a Jewish settlement in Gaza earlier this year.

Palestinians said it was the largest Israeli operation in Gaza during two years of fighting, involving about 60 tanks and armored vehicles.