Sixteen rockets were fired at Israel from Gaza on Thursday, and the Israeli Air Force carried out its first strike in Gaza for nearly a week, hitting a rocket launcher, the Israeli Army said.
The upsurge in violence follows the killing by Israeli undercover troops of four Palestinian militants in the West Bank city of Bethlehem on Wednesday, which shattered a five-day lull in hostilities and threatens Egyptian efforts to mediate a cease-fire.
Two of the rockets fired into Israel fell in the border town of Sderot, hitting a shed in the yard of a house and a soccer field.
The Israeli air force strike hit a rocket launcher that was ready to fire a rocket in northern Gaza at 3 a.m., but nobody was wounded, according to an army spokeswoman. It was the first Israeli strike in Gaza since last Friday night.
Among the four Palestinian militants who were killed Wednesday were two men, both in their 40s, who had been wanted by the Israelis for years: Muhammad Shehada, the commander of Islamic Jihad in Bethlehem, and Ahmed Balboul, a senior figure in Al Aksa Martyrs Brigades, a militia affiliated with Fatah, the party headed by President Mahmoud Abbas.
The four were killed while riding in a car in central Bethlehem, Israeli Army and Palestinian officials said. The army officials said that three rifles were found in the car, and that all four had been involved in attacks against Israeli civilians. Mr. Shehada, they said, headed a network that was in contact with Islamic Jihad headquarters in Syria.
In what it called an “initial response,” Islamic Jihad began firing rockets at Israel from Gaza early Thursday.
In an interview with The New York Times last July, Mr. Balboul said that he was hoping to work out an amnesty deal for himself with the Israelis. “Our intentions are turned toward negotiation,” he said, having come to a meeting in Bethlehem’s Manger Square unarmed.
A Fatah spokesman in Bethlehem, Hassan Abed Rabbo, said Wednesday that the Palestinian Authority had requested amnesty for Mr. Balboul but that the request was refused. Mr. Abed Rabbo insisted that as an Aksa Brigades leader, Mr. Balboul was not involved in any joint activity with Islamic Jihad, but that he may have been with the other armed men for a sense of security. According to Palestinian reports, Mr. Shehada used to belong to Fatah.
The other two in the car belonged to Islamic Jihad, Palestinian officials said. The Israeli Army identified all four as belonging to Islamic Jihad.
The raid came hours after Ismail Haniya, the leader of the Hamas administration in Gaza, laid out the conditions for a temporary cease-fire with Israel, including a cessation of all Israeli military operations in the West Bank.
The terms were the same as those offered by other Palestinian officials and Egyptian mediators in recent days: an Israeli commitment to a “comprehensive” truce including an end to “all acts of aggression” against the Palestinians; an end to “assassinations, killings and raids”; and the lifting of the months-long embargo on the Gaza Strip.
Hamas, the Islamic militant group, controls Gaza only. But Mr. Haniya said the truce should also apply to the West Bank, where the Israeli Army and the forces of Mr. Abbas hold sway.
An Islamic Jihad leader in Gaza, Khaled al-Batsh, said in an interview this week that his group had accepted an Egyptian request for a temporary calm in order to create conditions for a broader truce involving the West Bank and Gaza. He said the success of the lull was “in the hands of the Israelis. If they attack,” he said, the military wing of Islamic Jihad “will have to respond.”
After the raid, Islamic Jihad issued a statement calling on the Abbas-led Palestinian Authority to cease all negotiations with Israel and saying that “the continued Zionist aggression” had ended any talk of a truce.
Mr. Batsh repeated in a telephone interview on Wednesday that the raid had “destroyed all efforts” to achieve a lull.
Mr. Abbas’s office issued a statement late Wednesday calling the Israeli action a “savage crime” and describing the four dead as martyrs.
Speaking before thousands of students at the Islamic University in Gaza City on Wednesday, Mr. Haniya began by calling the recent round of hostilities between Israel and the militants in Gaza a “heroic” episode.
With barrages of Qassam rockets being fired at Israel from Gaza in late February and early March, Israel mounted an air and ground campaign in Gaza that left more than 120 Palestinians, including many civilians, dead. Two Israeli soldiers died in the fighting, and one Israeli civilian was killed by the rocket fire.
Mr. Haniya said that the Israeli military assault had “failed.”
A senior Israeli Defense Ministry official was in Cairo for talks on Sunday, but Israeli leaders have denied engaging in negotiations for a truce. They said that if Hamas stopped all the rocket fire and if the weapons smuggling into Gaza ceased, Israel would have no reason to attack, but they insisted that the army retained full freedom to act there.
Early Wednesday, another senior militant from Islamic Jihad was killed by Israeli fire in a village near Jenin, in the northern West Bank. Islamic Jihad issued a statement after the dawn attack threatening revenge.
Also on Wednesday, Israel’s deputy foreign minister, Majalli Whbee, told Army Radio that he had decided that Israel would boycott the Arabic-language satellite channel Al Jazeera because “its partial coverage is not credible and is damaging to us.”