Israel has sharpened its offensive against Palestinian militants with several air raids knocking out electricity around Gaza City.Offices of a prominent Fatah member and two militant groups were said to be the targets as over 350,000 homes were without power for two hours. The barrage came only hours after various Islamic and political representatives including those from Hamas and the ruling Fatah movement renewed a commitment to a ceasefire. Islamic Jihad later added its backing promising to stop rocket attacks on Israeli targets. Although the Israelis have welcomed the ceasefire declaration, the government said it wanted to see concrete results before halting its offensive. Israel’s tough approach has been provoked by a series of Palestinian attacks including the kidnapping and killing of an Israeli sweet seller from Jerusalem. There was a chilling new feature to the murder, as Sasson Nuriel was filmed, bound and blindfolded, in the manner of kidnap victims in Iraq. Israel’s Defence Minister, Shaul Mofaz has said security forces will continue to target Hamas leaders, who Israel describes as terrorists. Since the Israeli troop withdrawal from Gaza two weeks ago violence in the region has escalated, as Israel watches with growing concern the lack of control by the Palestinian authority over extremists. In a diplomatic development widely expected after the upsurge in violence the planned summit between the Israeli and Palestinian leaders due for the second of October has been postponed.