BALATA REFUGEE CAMP, West Bank (AP) _ Chanting ``revenge, revenge,'' thousands of Palestinians on Tuesday joined the funeral procession of an Islamic militant leader who Palestinian investigators said was killed by Israeli undercover troops.

Mahmoud Madani, 25, was hit by four bullets in the upper body Monday, shortly after leaving a mosque in the Balata refugee camp on the outskirts of the West Bank town of Nablus. He died later at a nearby hospital.

The governor of Nablus, Mahmoud Aloul, said Israeli undercover troops driving a car with Palestinian license plates infiltrated Balata and opened fire on Madani.

Aloul said other Israeli soldiers provided cover fire from an outpost on a mountain overlooking Balata to safeguard the getaway of the special unit.

Palestinian security officials questioned about a dozen camp residents about the incident, but no arrests have been made. Aloul said security would be beefed up at the entrances to Palestinian-controlled areas to prevent such killings in the future.

``Israel uses the policy of assassinations to stop the uprising, but this policy will only escalate the uprising, not stop it,'' said Aloul, referring to five months of Israeli-Palestinian fighting that has killed more than 400 people, most of them Palestinians.

Israel has not commented on the killing of Madani, a senior local activist in the Islamic militant group Hamas. Israeli security sources, however, have said Madani was involved in two recent car bomb attacks that killed two Israelis and injured about 100.

Palestinians have blamed Israel for the pinpointed killings of more than a dozen Palestinian activists. Israel has not acknowledged involvement in every case, but has said it will target Palestinians it suspects of attacking Israelis.

At Madani's funeral, Hamas activists said the killing would be avenged. ``We tell our martyr that we will continue resistance until we get our rights and liberate Jerusalem,'' said Jamal Mansour, a Hamas leader in Nablus. ``Israel must know that every day, new fighters will emerge from among the people.''

About 3,000 Palestinians joined the funeral procession, with the crowd chanting ``revenge, revenge.'' Eight jeeps carrying members of the Palestinian security forces led the marchers. Gunmen from Palestinian leader Yasser Arafat's Fatah movement fired shots in the air.

In the West Bank town of Tulkarem, two foreign workers at a local amusement park, one from the Netherlands and one from South Africa, were recovering at a Palestinian hospital Tuesday after being hit by stray bullets from an Israeli-Palestinian gun battle.

Ysbrandt van de Sande, 19, from The Hague, was hit by a bullet in the right leg. Martin Jansen Vuuren, 21, of Kleksdorp in northwestern South Africa, was injured when a bullet grazed him. The two were injured Monday night, while taking a break from dismantling the rides at the Dutch-run Merryland amusement park for transport to Egypt.

Meanwhile, Israelis rushed to obtain new gas masks Monday after Iraqi President Saddam Hussein threatened to take revenge on Israel as well as the United States for Friday's U.S. and British air strike against Iraqi anti-aircraft batteries.

The number of people arriving at the army's gas mask distribution centers almost tripled after official Iraqi media said Iraq would teach ``the Zionist entity'' (Israel) a lesson, a military official said.

On a normal day about 3,500 Israelis visit the 27 distribution centers throughout the country, said Col. Gilead Golan, who is in charge of distribution.

On Sunday the number jumped to 10,200, and by Monday afternoon it looked likely to reach the same total, Golan told Israel television at a crowded distribution center near Tel Aviv.

Most Israelis already have gas masks in their homes, left over from the 1991 Gulf War, when they were distributed as a precaution against chemical attacks from Iraq.