An Israeli helicopter air strike killed two Palestinian militants from Hamas in Gaza yesterday after a rocket fired by members of the Islamic group seriously wounded an Israeli civilian, medics said. Witnesses said the helicopter fired a missile at a group of men operating in the northern Gaza Strip. The Israeli army confirmed the strike, saying it fired after the militants launched a rocket. Three militants were also wounded.

The strike came hours after an Israeli man was wounded when a makeshift Hamas rocket landed near a school in the Israeli town of Sderot. A hospital official said the man was in serious condition.

Palestinian militants frequently fire rockets into Israel but seldom cause anything but light damage or injuries. The last time an Israeli was killed by a rocket strike was last July.

The killing of the Hamas militants was the first by Israel since the ruling Islamist group ended a 16-month truce on Friday after seven Palestinians, including three children, were killed on a Gaza beach on a day of Israeli shelling.

Israel has said the killings were a mistake. Israeli Prime Minister Ehud Olmert expressed condolences for the deaths yesterday and promised an investigation.

Since ending its truce, Hamas has fired around two dozen rockets and several mortar rounds into Israel. Israel has responded by firing artillery shells into Gaza.

Yesterday?s violence came as Olmert was due to leave on a visit to Britain and France, where he is expected to push for a continued strong European stance against Hamas and to discuss Iran?s nuclear programme.