More than 20 people, including children, were wounded in an Israeli air strike in Gaza City on Saturday night, Palestinian witnesses and medics said.The Israeli military confirmed the strike and said the target was the offices of militant group Hamas, which is committed to the destruction of Israel. A spokeswoman said the offices were in the grounds of a school and were used to transfer funds to suicide bombers and their families.The witnesses said nine children under the age of five were wounded, the youngest of whom was four months old. The al-Arqum school was founded by the Hamas’s spiritual leader Sheikh Ahmed Yassin who was killed in an Israeli airstrike in March 2003, witnesses said.Earlier an Israeli helicopter fired three missiles into the Gaza town of Khan Younis wounding two people, local witnesses and medics said. The target of the strike was a group of militants from the al-Aqsa Martyrs Brigades, part of Palestinian President Mahmoud Abbas’s Fatah faction. None of the militants, were hurt in the attack, witnesses added.Prime Minister Ariel Sharon today instructed the Army to act against Palestinian militants “without restrictions” using “any measure” to dismantle their infrastructure, dimming hopes for a peaceful co-existance in the Middle East. “I instructed that there are no restrictions on the use of any measures in order to strike at the terrorists, their equipment and where they find shelter”, Sharon told the Cabinet at the beginning of its weekly meeting. “The instructions are unequivocal. We do not mean a one-time action here”, he said. “This phenomenon must be stopped. It cannot continue under any circumstance,” Sharon said about the militants.Sharon, facing a leadership vote of his Likud party tomorrow, got support from the new US Ambassador to Israel, Richard Jones, who said that Washington understood Jerusalem’s response to weekend Palestinian rocket attacks on its southern town of Sderot and other Israeli communities in Negev.The air strikes came minutes after Israeli ministers decided to resume targetted killings on militants as part of a concerted response to the upsurge of violence by militant groups in the Gaza Strip.Meanwhile, a huge explosion that rocked Gaza City early on Sunday turned out to be a sonic boom apparently caused by an Israeli aircraft, Palestinian witnesses said. Three explosions on Saturday were due to Israeli air strikes.