Israel has warned a widescale military operation against Gaza could follow a string of air strikes which injured three Palestinian children. The strikes, on the western part of Gaza City, came in response to rocket attacks from Hamas-controlled Gaza into southern Israel. Foreign Office sources expressed concern at the threat of intensifying hostilities and urged the two sides to show restraint. Sky News Middle East correspondent Dominic Waghorn said the violence reflected a steady increase in tension in the region. "Almost 20 rockets were fired out of Gaza last month, one of them killing a Thai farm worker in southern Israel," Waghorn said. "Two Israeli soldiers were killed in a border clash a week ago, and there were airstrikes overnight. "Now Israel's deputy prime minister Silvan Shalom is threatening an escalation in Israeli military activity if the rocket fire does not stop."