Israel said it will not stop its offensive in the Gaza Strip despite a British-led UN Security Council resolution calling for a ceasefire.

Prime Minister Ehud Olmert's office said the military "will continue acting to protect Israeli citizens and will carry out the missions it was given."

The statement said Palestinian rocket fire showed the Security Council's call for a ceasefire "is not practical".

The news came after 14 out of 15 members of the security council backed the resolution. The United States abstained during the vote.

Foreign Secretary David Miliband said the UN had "served its purpose" after the vote, and urged the international community to "turn the words into changes on the ground".

As the vote was taking place, dozens more attacks occurred in Gaza with unconfirmed reports of a bomb flattening a five-storey apartment block in the northern part of the territory.

Hamas officials said the attack killed seven people, including an infant.

The fighting has so far killed more than 750 Palestinians and at least 14 Israelis.

Mr Miliband said after the vote: "The UN has served its purpose of speaking loudly and clearly and authoritatively and unequivocally.

"But we all have further responsibility. Responsibility for the parties on the ground, responsibility for the regional states...responsibility for the whole international community because this crisis in the Middle East affects us all."

He added: "We are all very conscious that peace is made on the ground while resolutions are written in the United Nations.

"Our job here is to support the efforts for peace on the ground and to help turn the good words on paper into changes on the ground that are desperately needed."

The resolution was based on a British-drafted text supported by the US and France - all veto-wielding members of the security council - and amendments by key Arab negotiators including the foreign ministers of Egypt, Saudi Arabia, Jordan, Morocco and Qatar.