An Israeli delegation is in Cairo this morning to discuss efforts to forge a ceasefire after six days of fighting between Israel and Gaza and amid international calls for the conflict to stop.

The meeting, about which the Israeli Foreign Ministry would not give details, comes amid news that the Israeli airstrike on a building in Gaza on Sunday, which left at least 11 people dead, including children, missed its target.

The strike on the two-storey house in Gaza City was intended to strike Yahiya Abiya, the head of Hamas's rocket programme. It is unclear whether he was killed, and the army said it was investigating why it missed its target. Ha'aretz reported the army stating that it was either that the site was incorrectly identified or that one of the munitions misfired.

Last night airstrikes on Gaza left another four people dead, said a Gaza health spokesman. It is thought the death toll now stands at 87, with at least 30 of those said to be terrorists involved in attacks on Israeli civilians.

Dozens of Israelis have been injured as terrorists continue to send rockets across the border, with one hitting the site of a school in Ashkelon. Although the Iron Dome defence system has been effective in intercepting missiles fired at towns and cities, including Tel Aviv, in total more than 1,000 rockets have been fired since Wednesday, with about a third stopped by the Iron Dome. The IDF reported that more than 100 of those fired by Hamas and other groups had actually crashed back into Gaza, injuring civilians in the Gaza Strip. The Israel authorised Operation Pillar of Defence following a sustained period of rocket fire at civilian populations in southern Israel.

The IDF has reported hitting at least 1,350 targets since fighting began on Wednesday.

In the US, politicians have urged Turkey and Egypt to assist efforts to mediate in the conflict and end the bloodshed on both sides.

Republican Senator Lindsey Graham told the media on Sunday evening that Egypt should be aware of the need for balance, or risk losing US aid. "Egypt, watch what you do. You're teetering with the Congress on having your aid cut off if you keep inciting violence between the Israelis and the Palestinians."

With Israeli troops said to be prepared to go in on the ground within the hour, President Obama backed Israel's right to defend itself but said it would be preferable for both sides if a ground offensive did not occur.

William Hague, the UK Foreign Secretary, echoed his comments, while backing Israel's position in taking on Hamas, who he said was principally responsible for the fighting. He said: "A ground invasion is much more difficult for the international community to sympathise with or support, including the United Kingdom."

A Hamas spokesman this weekend said that the Palestinian people were "united to confront the aggression" and considered it their "right… to resist the occupation".