JERUSALEM -- Israel launched air raids yesterday in Gaza, killing at least two Palestinians.
It also amassed tanks and troops along the border for the first time since Israeli troops withdrew from the area this month.
The actions were in response to Palestinian rocket attacks Friday and yesterday on towns just outside the Gaza Strip. Although no one was killed in the strikes, they put pressure on Prime Minister Ariel Sharon to make good on pledges to respond harshly.
The attacks also appeared to undermine Sharon's assertion that Israeli security would improve after the withdrawal from Gaza, and they provided fodder to critics in his own Likud party.
Among those critics is the former prime minister, Benjamin Netanyahu. They are hoping at a key meeting tomorrow to begin the process of removing Sharon as the Likud party's leader.
Top security officials met twice yesterday to decide what to do about the rocket attacks, which militant groups described as retaliation for Israeli military action. The Israeli newspaper Ha'aretz reported that the Security Cabinet had decided that Israel would fire artillery against the Qassam launchers in the strip, and approved the renewal of targeted assassinations against members of the Islamic extremist group Hamas, as well as the continuation of air attacks as needed.
Defense Minister Shaul Mofaz said Israel's response ''needs to be crushing." He announced a total closure of the West Bank and the Gaza Strip. ''We have to make it clear to the Palestinians that Israel will not let the recent events pass without a response," Mofaz said.
Hours after it was issued, Israeli helicopters fired missiles at two cars in Gaza's Zeitoun neighborhood. The Israeli army said in a statement that militants from Hamas were traveling in one of the vehicles and that the other contained weapons belonging to the group.
The missiles shattered both cars and set them ablaze, according to witnesses. The Palestinian Interior Ministry said two passengers were killed, but hospital officials put the death toll at four.
Early today, the Israeli military said it had arrested 190 wanted Palestinians overnight in the West Bank, most of them members of the Hamas and Islamic Jihad movements, the Associated Press reported. The arrests were still underway this morning, the military said.
Late yesterday, an Israeli aircraft attacked a school in a crowded Gaza City neighborhood, wounding at least 17 people, the AP said, quoting Palestinian medical officials. The blast struck the Arkam school, which was established by the late founder of Hamas, Sheik Ahmed Yassin. The army said the building was used by Hamas to raise money, recruit militants, and assist families of suicide bombers.
Israel carried out regular air raids on Gaza for most of the Palestinian uprising, but had largely stopped such measures after the two sides reached a cease-fire in February.
The Palestinian information minister, Nabil Shaath, said Sharon was trying to destroy the truce with ''an act of criminal aggression."
Hamas, which has sent more suicide bombers to kill Israelis than any other Palestinian faction, vowed to avenge the killings and called on its members to strike at Jews ''in every spot of our occupied land." The group also said it holds Israel responsible for the deaths of at least 15 of its supporters in an explosion at a rally Friday.
Israel denied involvement. And the Palestinian president, Mahmoud Abbas, said the deaths were caused by the explosion of Hamas ammunition at the rally.
''What happened yesterday is what we always feared would happen and what we always warned against," Abbas said in a speech broadcast yesterday on Palestinian radio. ''Today, we are required more than ever to end this tragedy."
Abbas had been trying to broker a deal requiring all the armed factions to end the brandishing of weapons and ammunition at rallies. Hamas said yesterday that it would now abide by the ban.
Abbas, like Sharon, faces a political challenge to his leadership. Hamas, which rejects any form of conciliation with Israel, is expected to take a large bite out of Abbas's power when Palestinians elect a new parliament in January.
But in the case of the 77-year-old Sharon, the challenge comes from within the ranks of his faction. Members of the Likud Central Committee -- the Likud party's key decision-making body -- are scheduled to vote tomorrow on a proposal to hold primaries in November instead of next year, an initiative Sharon describes as a putsch.
General elections in Israel are not scheduled for another year, but early primaries in Likud could set off a chain reaction that leads to an early national vote, possibly by February. Netanyahu hopes to capitalize on the dissent in Likud over the Gaza withdrawal.
A poll published Friday in the newspaper Yedioth Ahronoth indicated that Netanyahu was leading Sharon by a small margin in a party vote. But it also suggested that among a cross-section of Israeli voters, Sharon appears to be much more popular.