JERUSALEM - Hundreds of Israeli police in riot gear stormed a disputed holy site today, firing tear gas, stun grenades and plastic bullets to disperse Muslim worshippers throwing stones and shoes at them.

After the initial clashes, thousands of Palestinians barricaded themselves in two mosques in the walled compound for about two hours, before police agreed to let them leave without threat of arrest.

More than 20 Palestinians were hurt and at least nine arrested in the most violent confrontations at the Al Aqsa Mosque compound, known to Jews as the Temple Mount, since the outbreak of Israeli-Palestinian fighting in September 2000.

Hours earlier, Israeli Prime Minister Ariel Sharon said in published interviews that Palestinian leader Yasser Arafat and Lebanese guerrilla chief Hassan Nasrallah could become targets for assassination. Sharon's threats were the most explicit yet against his arch foes.

Sharon also said he would withdraw from all of the Gaza Strip and the West Bank settlements of Ganim, Kadim, Homesh and Sanur, for the first time revealing the scope of his unilateral "disengagement" plan. His spokesman confirmed the remarks. Sharon also said the withdrawal would be under way within a year.

The confrontations at the Jerusalem holy site revered by both Muslims and Jews erupted after Muslim noon prayers.

Initially, several Palestinian youngsters threw stones at police deployed nearby. In response, hundreds of officers with helmets and plastic shields burst into the walled compound, shooting tear gas, stun grenades and plastic bullets, witnesses said.

The crowd of stone throwers grew to several hundred, and worshippers also threw shoes at the baton-wielding officers. More than 20 Palestinians were injured, Muslim clerics said, and police said they arrested nine Palestinians. An Associated Press Television News cameraman was injured in the ear when a stun grenade went off nearby, and he required stitches.

After the initial clashes, thousands of Palestinians barricaded themselves in two mosques in the compound. The Islamic Trust, which administers the Al Aqsa Mosque compound, negotiated with police to allow worshippers to leave. After about two hours, the standoff ended peacefully.

In the diplomatic arena, Sharon has said he would let his divided Likud Party make a final decision on the withdrawal plan. Sharon is to hold a binding referendum among 200,000 party members after his return from an April 14 meeting with President Bush. Recent polls suggested that while Sharon has an advantage, the gap is too small to assure approval of the Gaza plan.

Sharon's interviews with the Maariv, Yediot Ahronot and Haaretz dailies, given ahead of next week's Passover holiday, were seen as the opening of his campaign for the withdrawal plan.

Maariv quoted him as saying Israel would withdraw from all of Gaza, only retaining control over a patrol road between southern Gaza and the Egyptian border, to prevent weapons smuggling. "He said very clearly we are not going to stay in Gaza," Sharon's spokesman Raanan Gissin said today.

Sharon initially considered retaining three settlements in northern Gaza. There had also been debate over how many West Bank settlements to evacuate, and it appears Sharon settled for the smallest proposed number of four.

"We need to get out of Gaza, not to be responsible any more for what happens there," Sharon told Maariv. "I hope that by next Passover we will be in the midst of disengagement, because disengagement is good for Israel."

The prime minister told Yediot that after the withdrawal Israel would consider cutting off water and electricity to Gaza if attacks against Israelis continue.

Asked by Haaretz whether Arafat and Nasrallah are targets for assassination, Sharon said: "I wouldn't suggest that either of them feel immune ... Anyone who kills a Jew or harms an Israeli citizen, or sends people to kill Jews, is a marked man. Period."