Foreign Secretary William Hague has voiced Britain's support for Egyptian efforts to broker a ceasefire in Gaza as he met EU counterparts in Brussels to discuss the crisis.
Some 90 Palestinians - around half of them civilian non-combatants - are reported to have been killed by Israeli air strikes on Gaza, launched last Wednesday in response to a wave of rocket attacks on Israeli towns and cities from the Palestinian enclave.
Arriving in Brussels for a meeting of foreign ministers from the 27 EU states, Mr Hague made clear that Britain blames Gaza's Hamas rulers for precipitating the conflict, but also urged Israel to "de-escalate" the violence.
Mr Hague said: "We will be discussing today among the foreign ministers the terrible situation in Gaza, the continuation of rocket fire from Gaza on to Israel that, in our view, has precipitated the current crisis.
"We want efforts to negotiate a ceasefire to succeed. I spoke to the Egyptian foreign minister about that yesterday and Egypt are making strong efforts in that regard, with our support.
"Of course, part of any ceasefire has to be a cessation of rocket attacks against Israel, but everyone has responsibilities. Israel has responsibilities too to take every opportunity to de-escalate the violence, to avoid civilian casualties, to observe international humanitarian law. The Prime Minister and I have both spoken to our Israeli counterparts over the weekend."
The World Health Organisation (WHO) said it is deeply concerned about the situation and its impact on the health and lives of civilians in the area, while charity Save the Children said hundreds of thousands of youngsters are trapped in houses in Gaza facing prolonged power cuts and depleting supplies of food and water.
A group of 38 charities issued a plea for world leaders to use their influence to secure a ceasefire in Gaza to protect civilian lives and infrastructure.
United Nations secretary-general Ban Ki-moon was due to arrive in Cairo to add his weight to calls for a ceasefire. "This must stop," said Mr Ban. "Any further escalation will inevitably increase the suffering of the affected civilian populations and must be avoided."
A spokesman for the government of prime minister Benjamin Netanyahu declined to comment on reports in the Israeli media that a delegation from Israel had also been to the Egyptian capital for talks.