Israel launched two air strikes in Gaza on Friday, killing a Palestinian militant and wounding six people as rockets fired from the enclave slammed into its southern region, threatening to unravel an Egyptian-brokered truce.

Palestinian officials in Gaza said the militant killed in a strike on al-Bureij refugee camp was a member of a pro al-Qaida fringe Salafist Islamist group which Israel blamed in part for a deadly cross-border attack from Egypt's Sinai on Monday.

A second air strike launched after darkness fell wounded four other men in northern Gaza, Hamas medical officials said.

It was not immediately clear whether any of them were militants.

Israel confirmed both strikes, saying in the first instance its fighter aircraft targeted a group preparing to fire rockets at southern communities and the second raid struck gunmen as they were shooting a rocket that hit near the city of Ashkelon.

In all, four rockets fired from Gaza slammed into southern Israel on Friday, and the total for the week, since Monday, came to more than 130 rocket shootings, Israel said.

The rocket attacks have caused no casualties but sowed panic in a region home to a million Israelis where air raid sirens send many scurrying for cover, disrupting normal life and in turn pressuring leaders to authorize more retaliatory raids.

Friday's violence broke a two-day lull in cross-border attacks when Hamas militants in Gaza said they would abide by an Egyptian-brokered deal to withhold fire as long as Israel also stopped shooting.

Egypt has feared that the fighting near its borders could spark wider violence at a time when Cairo was confronting fresh popular protests over the uncertain outcome of a presidential vote.

Hamas's involvement in the fighting had added to Egypt's and Israel's concerns, as the Islamist group which governs Gaza had largely avoided direct involvement in confrontations with Israel since a devastating 2009 Israeli offensive.

Hamas did not claim any involvement in Friday's violence, a sign that the latest conflagration may be more easily contained.

The militant killed on Friday was the ninth person in Gaza killed by Israeli air strikes since Monday, including a 14-year-old boy. Israel launched these attacks after an attack from Egyptian Sinai that killed an Israeli man.

Israel responded on Monday by killing two of the attackers, then targeted militants in Gaza including some it blamed for the Egyptian border incident and others it said fired rockets.

Officials in Gaza had initially identified the militant as a member of the Popular Resistance Committees, a group often involved in rocket shootings at Israel, but later the Salafists said he had actually been a member of their group.