In a surge of violence that followed days of relative calm, Israeli troops killed six Palestinians in two separate confrontations Sunday evening near the border with the Gaza Strip, the military said.

The shootings came only hours after senior Israeli security officials said that attacks by Palestinian militants had dropped significantly since Palestinian leader Yasser Arafat's speech two weeks ago calling for a cessation of violence.

In the first shooting, troops in an armored vehicle shot dead three Palestinians crouching about 20 yards from the perimeter fence of the Jewish settlement of Alei Sinai at the northern edge of the northern Gaza Strip, the army said.

The army initially said the Palestinians had opened fire on the troops, but later retracted the statement. Palestinian witnesses in a nearby village said the Israeli forces fired at least four tank shells and machine guns. Back in October, two Palestinian attackers entered the settlement and killed two Israelis before being killed themselves.

Several hours later and only a short distance away, Israeli soldiers shot and killed three armed Palestinians who had crossed Gaza's northern border and entered Israel, according to a statement issued by the office of Prime Minister Ariel Sharon.

The trio was spotted by Israeli forces and ordered to halt. One of the Palestinian gunmen opened fire, and all three were killed by Israeli return fire, Sharon's office said.

Before the two shootings, Israeli security officials had given an upbeat assessment of the ongoing battle with the Palestinians.

Defense Minister Binyamin Ben-Eliezer told a Cabinet meeting Sunday that the number and severity of Palestinian attacks was down for a second week in a row.

But Sharon said the Palestinians needed to do much more. He told the Cabinet he would not reopen peace talks "as long as the Palestinians have not taken the vital steps to arrest terrorists and punish them."

Palestinian attacks — including shootings, bombings, grenade attacks, assaults and stabbings — have dropped from an average of 18 a day before Arafat's speech to 11 a day since then, the army said.

The army did not characterize those attacks, but the decline in Israeli fatalities and serious injuries has been dramatic.

A total of 37 Israelis were killed in the first half of December, before Arafat delivered his televised speech on Dec. 16. Since then, one Israeli has been killed in political violence, an army medic shot dead during an attack along the border with Jordan on Dec. 25; it wasn't clear who carried out that attack.

More than 70 Palestinians have been killed by Israeli security forces this month. Most died in the first half of the month amid almost daily clashes.

After a quiet day Sunday, Palestinian gunmen fired Sunday night on an Israeli armored personnel carrier in the northern Gaza Strip, near the Jewish settlement of Alei Sinai, the army said. Three Palestinians were killed in return fire, the army added. Palestinian witnesses said the Israelis fired at least four tank shells.

Shortly after Arafat's Dec. 16 speech, the militant Hamas movement said it would stop suicide bombings inside Israel proper, but did not specifically rule out attacks against Israeli settlers and soldiers in Gaza and the West Bank.

The Palestinian security forces have been cracking down on militants, taking about 200 into custody during December. The moves prompted clashes between Palestinian police and supporters of Islamic militant groups in which seven Palestinians were killed.

However, Sharon has said repeatedly that he has not been impressed by the Palestinian actions. Sharon spokesman Raanan Gissin said the Palestinians had arrested only 10 of the 33 suspects on a list presented to the Palestinians by Israel.

Sharon has insisted on at least seven days of complete calm before he would consider implementing an international plan designed to lead to a resumption of peace talks.

"Attacks are going down, but there are still alerts for suicide bombings and car bombings. This is no cease-fire," Gissin said. "Arafat still hasn't made the strategic decision to implement one."

The Palestinian position is that absolute calm is not possible, and peace talks should resume as soon as possible.