Palestinian boys have a farewell look at the body of a Hamas militant killed in overnight fighting. Photograph: Suhaib Salem/Reuters  An Israeli air strike has killed three militants in the Gaza Strip, the Islamist group Hamas said, after an overnight clash on Friday killed a fourth Palestinian gunman and wounded five Israeli soldiers.  It was the worst violence between Israeli and Palestinians in Gaza since a ceasefire was agreed last November.  The Israeli military said its aircraft targeted a tunnel used by militants to help attack Israelis and accused Hamas of breaching truce terms.  A Hamas source said three of its men were in the tunnel and were killed in the blast.  Hours earlier, one Palestinian militant was killed and five Israeli soldiers wounded after violence broke out when Israeli forces detonated part of a separate tunnel recently uncovered stretching from Gaza into Israel.  Hamas has said it dug the tunnel, which was uncovered last month. Israel says the underground chamber ran for a mile and was intended to let militants cross deep beneath the border fence for surprise attacks.  At a sermon before Friday prayers, senior Hamas leader Khalil Al-Hayya, said the clash showed Hamas fighters were "alert and ready with their fingers on the trigger".  "We are not interested in an unjustified escalation but we have the right to defend our people," he told reporters.  The violence came at a difficult time for Hamas, which lost its most powerful backer in July, when Egypt's Islamist president Mohamed Morsi was ousted by the military. Relations with Egypt have deteriorated sharply since.  The head of Israel's southern command, Sami Turgeman, said Israel was not seeking an escalation in violence. "Quiet will be answered with quiet. An attack will draw a painful response," he told reporters.  The Israel-Gaza frontier had been mostly peaceful for the past year following the Egypt-brokered ceasefire.  However on Monday, Gaza militants fired two rockets at a southern Israeli coastal city and Israel bombed what it said were two concealed rocket launchers in northern Gaza. There were no casualties.  A senior Israeli defence official said he did not expect the latest round of violence to lead to an escalation along the border. "As far as I can tell from Hamas, they are deeply deterred (by Israel) and I estimate that quiet will return," the official, Amos Gilad, told Israel Radio.  The Palestinian Authority, Hamas's western-backed rivals who exercise limited rule in the Israeli-occupied West Bank, resumed peace talks with Israel in July.  Tension has also mounted in the West Bank, where eight Palestinians have been shot dead by Israeli soldiers and three Israelis have been killed since the talks began.
Israeli air strike and overnight fighting follows discovery of tunnel in worst violence in Gaza since 2012 ceasefire