GAZA CITY -- Tens of thousands of Hamas supporters paraded through downtown Gaza City yesterday, threatening to end a monthlong truce if Jewish extremists follow through on a pledge to hold a rally at a disputed holy site in Jerusalem next week.
In Beirut, the leader of the militant Hezbollah group warned Israel that such attacks would trigger an Arab and Muslim response.
Sheik Hassan Nasrallah urged Arab and Muslim peoples and governments to act to stop any possible attack by Jewish extremists on the disputed holy site.
Israeli authorities, trying to avert violence, tightened access at the site and stepped up preparations to bar Jewish demonstrators from the area during tomorrow's planned march.
The hilltop site in Jerusalem's Old City is known to Jews as the Temple Mount and to Muslims as the Noble Sanctuary. The Al Aqsa Mosque compound, Islam's third-holiest site, is located there, built above the ruins of the biblical Jewish temples. Jews opposed to Israel's planned withdrawal from the Gaza Strip want to rally at the site in a move aimed at sabotaging the pullout.
Jewish access to the compound has been strictly limited since Israel captured east Jerusalem in the 1967 Mideast war, and a large-scale rally would raise tensions with the Palestinians. A September 2000 visit to the compound by Prime Minister Ariel Sharon, who was then the opposition leader, touched off Palestinian riots that escalated into 4½ years of bloodletting.
In Gaza City, some 40,000 Hamas supporters gathered after weekly prayers yesterday and warned that the rally could lead to an immediate resumption of violence. Waving green Hamas flags and posters of the Al Aqsa Mosque, the protesters chanted, ''We will redeem Al Aqsa with our souls and our blood!" and ''They will only enter Al Aqsa over our dead bodies!"
Hamas, the largest militant group, and other violent Palestinian factions agreed last month to honor a cease-fire declared by Sharon and Palestinian leader Mahmoud Abbas on Feb. 8.
Nizar Rayan, a top Hamas official, said the group would resume its attacks on Israeli targets if Sunday's march takes place.
''We will move with our rockets and our warriors in order to defend Al Aqsa and to protect it. Not only Hamas, but all the Palestinians and Muslims," he said.
In the nearby Jabaliya refugee camp, some 1,200 masked and armed members of Islamic Jihad, another militant group, marched and warned of war if the mosque is threatened. ''Israel will be fully responsible for all the consequences if the Zionist troops storm Al Aqsa, if the settlers defile Al Aqsa Mosque," said Islamic Jihad spokesman Khaled Batsh.
Leaders of the Al Aqsa Martyrs' Brigades, a violent group affiliated with Abbas's Fatah movement, also have threatened violence. Hezbollah's Nasrallah warned Christians that their holy sites in Jerusalem faced the same threat.
With Israeli police and Palestinians on edge, Muslim prayers yesterday at Al Aqsa in Jerusalem were being watched as a potential flash point.
Muslim leaders had pledged to bring thousands of worshipers to the area, touching off fears of confrontations between Muslims and Jews. But the afternoon prayer, which drew about 10,000 worshipers, concluded without incident.
Thousands of police guarded the site, which is adjacent to the Western Wall, Judaism's holiest shrine, and were to remain there through tomorrow, police said.
''There might be an attempt by these [Jewish] groups or others to reach the Western Wall, but nothing will happen on the Temple Mount," Public Security Minister Gideon Ezra of Israel told Channel Two television.
Jewish extremists say that in July, when the Gaza evacuation is to begin, they will bring tens of thousands of people to the Temple Mount, forcing police to divert their attention from the pullout to Jerusalem. Tomorrow's rally is seen as a dry run. Israeli security officials have banned pullout opponents from rallying at the compound tomorrow, but organizers say they will hold the gathering nearby.
Abbas said yesterday that the Palestinians have been in contact with Defense Minister Shaul Mofaz of Israel about the rally. ''We have a pledge from the Israelis that they will prevent any aggression on Al Aqsa Mosque, and we hope so," Abbas said.
Under Sharon's withdrawal plan, Israel will pull out of all 21 settlements in the Gaza Strip and four small settlements in the West Bank over a four-week period beginning in July. About 9,000 Jewish settlers will be moved from their homes.
En route from Rome to Washington yesterday, President Bush said he will tell Sharon that he should adhere to obligations of a Mideast peace plan that calls for a construction freeze on all West Bank settlements.