The Israeli prime minister has expressed regret at the killing of Palestiniancivilians on a beach in Gaza.Ehud Olmert made the comments at a cabinet meeting two days after the event which sent shockwaves through the Palestinian territories. He said: “As a result of an incident which has not yet been thoroughly checked, seven family members were killed. We express our deep regret for this.” He added that the government had ordered an investigation, the results of which would be made public. The tragedy has not deterred Israel from pursuing its fight against Palestinian militants. This morning three people were killed in separate air strikes in Gaza. The Israelis said they were responding to rocket attacks. Meanwhile tensions show no sign of easing between the Hamas government and Mahmoud Abbas. The president is holding firm with his referendum on July 26 that would implicitly recognise Israel, despite pleas from prime minister Ismail Haniyeh that it should not be held. One of the few things the two men could agree on was condemnation of the Israeli raid on the Gaza beach which left a young girl’s immediate family dead. Abbas has symbolically adopted her. The attack prompted the armed wing of Hamas to break off its informal 16-month truce. One spokesman has said that suicide attacks which have killed hundreds of Israelis might now resume.