JERUSALEM — Palestinian militants detonated a bomb next to an Israeli army patrol near the Gaza Strip on Tuesday and Israeli soldiers quickly crossed the border in search of the attackers in the first serious clash since a cease-fire went into effect more than a week ago.
Israeli military says one soldier was killed, three were wounded in the attack.
Heavy gunfire was audible along the border in central Gaza and Israeli helicopters hovered in the air, firing machine gun bursts, Palestinian witnesses said. The Israeli military said the bomb targeted an Israeli patrol near the border community of Kissufim but would not provide further details.
There was no claim of responsibility for the attack.
An Israeli jet broke the sound barrier and set off a loud sonic boom over Gaza City not long afterward, possibly as a warning, but there were no further reports of Israeli retaliation. Since ending a punishing three-week offensive against Hamas on Jan. 17, Israel has said it will respond in force to any attack from Gaza.
Israeli troops crossed the border fence into Gaza to search the immediate area of the bombing, defense officials said. They spoke on condition of anonymity under military guidelines.
Israel closed its crossings into Gaza to humanitarian aid traffic after briefly opening them Tuesday morning. Gaza border official Raed Fattouh said Israeli officials informed him the closure was due to the attack.
In what appeared to be an unconnected incident Tuesday, Palestinian security officials said Israeli troops along the border shot and killed a 27-year-old man and wounded two others. Dr. Moaiya Hassanain of Gaza's Health Ministry said the dead man was a farmer. The military had no immediate comment.
Israel and Gaza militants have been holding their fire since Israel ended its offensive, which was aimed at halting rocket fire from the territory. Israel announced a unilateral cease-fire on Jan. 17, and that was followed by a similar announcement from Gaza militants.
In the days immediately following the cease-fire there was shelling by Israeli gunboats and some gunfire along the border — including the killing of two men Palestinian officials identified as farmers — but there were no serious clashes until Tuesday.
Although there was no claim of responsibility for Tuesday's attack, Mushir al-Masri, a Hamas leader, said Israel was to blame for continuing to fire into Gaza. Al-Masri said his group had not agreed to a full cease-fire but only to a "lull" in fighting.
"The Zionists are responsible for any aggression," he said.
Egypt is currently trying to negotiate a longer-term arrangement to allow quiet in the coastal territory of 1.4 million people, which has been ruled by the Islamic militants of Hamas since June 2007.
Israel wants an end to Hamas rocket attacks and guarantees that Hamas will be prevented from smuggling weapons into Gaza from Egypt. Hamas has demanded that Israel and Egypt reopen Gaza's border crossings, which have been largely closed since Hamas took power. The crossings are Gaza's economic lifeline.
The Israeli offensive killed 1,285 Palestinians, more than half of them civilians, according to records kept by the Palestinian Center for Human Rights. Thirteen Israelis, including three civilians, were also killed during the fighting.