Israel killed seven Hamas militants in a series of air strikes after the group detonated two jeeps packed with hundreds of kilograms of explosives at an Israeli crossing on the Gaza border.
Two of the militants were killed early Sunday.
Israeli Defense Minister Ehud Barak visited the area of Saturday's twin suicide attacks, which wounded 13 soldiers, and warned Hamas would "bear the consequences."
However, an immediate Israeli offensive appears unlikely — Israelis are currently marking the Jewish Passover holiday, and in May will celebrate their country's 60th birthday, with U.S. President George W. Bush attending.
The Islamic militant Hamas said Saturday's attack on the Kerem Shalom crossing was part of a campaign to break the nearly yearlong blockade of the Gaza, by force if necessary. Israel and Egypt virtually sealed Gaza after Hamas seized control of the territory by force.
In Damascus, former U.S. President Jimmy Carter met with senior Hamas leaders on Friday and Saturday, defying U.S. and Israeli warnings that doing so would grant the group legitimacy. Hamas officials said Gaza's closure and a possible Israel-Hamas prisoner swap were discussed. They said the group did not respond to Carter's request that it halt rocket fire on Israeli border towns or that it agree to talk to Israeli Deputy Prime Minister Eli Yishak about a prisoner exchange.
Following the crossing attack, Israel targeted Hamas militants in a series of missile strikes, killing seven. Of those, five were killed Saturday and two early Sunday. Four Hamas gunmen were wounded in Sunday's strikes in northern Gaza and east of Gaza City, medics said.
A senior Hamas official, Sami Abu Zuhri, warned the crossings would be targeted again. Saturday's attacks "are the beginning of the explosions that Hamas has warned of," he said. "If the parties don't intervene quickly to save Gaza and break the siege, what is coming will be greater."
The attack on Kerem Shalom started at about 6 a.m. Saturday, said Maj. Gen. Yoav Galant, the top army commander in the area. Hamas militants drove an armored personnel carrier and two jeeps made to look like Israeli army vehicles toward the crossing under the cover of morning fog as Hamas pounded the border area with heavy mortar fire.
The armored personnel carrier broke through the perimeter fence, enabling the two jeeps to enter the crossing. One jeep was detonated near an army watchtower and the second near a patrol. Thirteen soldiers were wounded in the second blast, including eight who were hospitalized. Four Hamas attackers, were killed, the army said.
Galant said Hamas apparently tried to cause a large number of casualties and to kidnap soldiers.
"This is an attack the likes of which we have not seen since disengagement," Galant said, referring to Israel's pullout from Gaza in September 2005.
Israeli government spokesman Mark Regev said Hamas is showing disregard for the welfare of Gaza's residents by attacking the crossings.