William Hague has pinned the blame for the current flare-up in the Middle East on Hamas, following a spate of killings on both sides of the border.
Three people have died in southern Israel after a four-storey building in the town of Kiryat Malachi was hit by a rocket from Gaza.
It follows a strike which killed 11 Palestinians yesterday, including Hamas' military chief and several children.
"Hamas bears principal responsibility for the current crisis," the foreign secretary said.
"I utterly condemn rocket attacks from Gaza into southern Israel by Hamas and other armed groups.
"Hamas and other armed groups in Gaza should cease attacks against Israel immediately. I call on those in the region with influence over Hamas to use that influence to bring about an end to the attacks."
Israel's strike has resulted in over 130 rockets being fired from Gaza. The spasm of violence follows a period of gradually increasing cross-border tension. Hundreds of rockets have been fired, while Israel has carried out several air strikes.
Hague, who has been a vocal opponent of Israeli settlements, did not limit his criticism to Hamas.
"I also strongly urge Israel to do their utmost to reduce tension, avoid civilian casualties and increase the prospects for both sides to live in peace," he said.
"It is imperative to avoid the risk of a spiral of violence. The escalation of the conflict would be in no one's interest, particularly at a time of instability in the region."
Labour shadow foreign secretary Douglas Alexander struck a similar tone, saying: "The recent rocket attacks into southern Israel that have led to this latest response deserve our categorical condemnation but Israel must at all times act in accordance with international law."
But the Green party broke the Westminster consensus by backing the Palistinian side in a strongly-worded statement criticising the Israeli action.
"There can be no peace in the Middle East without justice for the people of Gaza," Green party international co-ordinator Derek Wall said.
"The attack which has killed many civilians, announced on Twitter and widely seen as part of an election campaign is both cynical and sordid."
Palestinian leader Mahmoud Abbas has cut short a trip to Sweden to deal with the escalating crisis.