JERUSALEM (AP) _ Israeli authorities set up roadblocks across southern Israel and cut off bus service in the Gaza Strip on Sunday as they began final preparations to begin dismantling all 21 Jewish settlements inside Gaza.

Israeli troops were to seal off the settlements at midnight (5 p.m. EDT), marking the start of the withdrawal, the first time Israel will pull out of settled land Palestinians want for a future state. Two days later, soldiers will begin forcibly removing any remaining settlers.

As of Sunday, thousands of residents were vowing to resist eviction. Other opponents of the pullout have threatened to hold massive demonstrations and to run the roadblock on the Gaza border to create chaos and torpedo the withdrawal.

Police spokesman Avi Zelba said authorities set up a cordon of roadblocks in southern Israel on Sunday to prevent opponents from interfering. Only residents of southern Israel and those with a legitimate reason for being there will be allowed to cross.

Meanwhile, Palestinian security forces, along with several Egyptian officers, began deploying near Jewish settlements in Gaza. By Monday, thousands of Palestinian troops will be deployed near settlements, to prevent militants from reaching the area.

Vice Premier Shimon Peres gave a pep talk to Israeli troops stationed near the Gaza border, telling them their coming task was crucial to protecting democracy.

``The settlements must be evacuated they cannot stay here,'' he told reporters. ``I understand that there are feelings. I have sympathy (for the settlers), but they cannot replace a national choice.''

Resistant settlers also made last-minute preparations, with their leaders issuing instructions on how to break the morale of soldiers sent to carry out eviction orders, according to the Yediot Ahronot daily.

The settlers were told to give children's drawings to the soldiers and to take pictures of troops, telling them that history will remember them for their crimes, the newspaper reported.

Settlers also planned to seal off their communities early Monday to prevent soldiers from delivering eviction notices.

The army closed the checkpoint into the Gush Katif cluster of settlements in southern Gaza to everyone but residents weeks ago, but thousands of protesters managed to infiltrate. The army said Sunday that as many as 4,000 disengagement opponents might be inside the settlements; settlers said the figure was much higher.

``I think that's a sign that a lot of soldiers are also protesting in their way by letting people come in,'' said Anita Tucker, a resident of the Netzer Hazani settlement.

Brig. Gen. Dan Harel, the military commander in charge of the pullout, said the infiltrators would have no impact on the pullout.

``They won't prevent us from carrying out the disengagement at the time, moment and way that we see fit,'' he told Army Radio.

Meanwhile, hundreds of settlers gathered at the Gush Katif cemetery singing traditional prayers of redemption as part of a ceremony commemorating the Tisha B'Av holy day marking the destruction of the Jewish Temples. The cemetery's 49 graves are to be moved as part of the pullout.

``Go to the holy patriarchs, the holy matriarchs, tell them `We want to stay here,''' Rabbi Yosef Elnikaveh said, symbolically addressing the dead at the ceremony. ``Tell them you don't want anyone to touch you. Tell them you don't want them to open your graves, that you want your graves to remain and be opened only upon the resurrection of the dead.''

Another Gaza settler, Yoav Itzhaki, said he and some settlers wanted to establish their own authority in the region, autonomous from Israel and the Palestinian Authority.

``The state of Israel does not have the right to expel the local residents,'' Itzhaki told Army Radio, reading from the group's charter. ``In light of this, we, the residents of the Katif Strip, have decided to stay in our homes and to establish the Jewish Authority of the Gaza Strip.''

Police had expected large crowds Sunday at the Western Wall, the Jewish holy site in Jerusalem, as a sign of protest during the Tisha B'Av fast day. However, the crowds were smaller than feared, possibly because of the August heat.

Israel's Islamic Movement called on Muslims to gather at the adjacent Haram a Sharif, the disputed holy site claimed by both Muslims and Jews, to protect it. Thousands of police were sent to the area to prevent a possible outbreak of violence between Arabs and Jews, police said.

About 55,000 Israeli troops and police are expected to take part in the pullout from the settlements in Gaza and four others in the northern West Bank. Some of the forces will remove the settlers from their homes, others will prevent protesters from interfering; still others will protect troops and settlers from attacks by Palestinian militants trying to create the impression they are driving the Israelis out.

The Israelis and Palestinians also opened a joint-operations center on the Gaza border to help them respond to any violence, Palestinian Interior Ministry spokesman Tawfiq Abu Khoussa said. Israel has promised to retaliate harshly if fired on during the pullout.

Israeli and Palestinian commanders held their final security coordination meeting Sunday, exchanging maps of troop placements in preparation for the deployment later Sunday of 7,500 Palestinian troops along the outskirts of the Gaza settlements to deter militant attacks, the Israeli army said.