Israeli air strikes killed the head of Islamic Jihad's rocket force in Gaza early on Thursday, part of an operation that has killed 25 people including women and children this week and that has been met with hundreds of rockets fired from the enclave.

Egypt was set to host senior Islamic Jihad official Mohammad al-Hindi in Cairo as part of mediation efforts to end the fighting, two Islamic Jihad officials and a foreign diplomat told Reuters.

Ali Ghali was the fourth senior Islamic Jihad commander killed since Israel began striking Gaza in pre-dawn raids on Tuesday. The death toll in the raids includes at least five women and five children.

The military said Ghali had helped oversee the launch of rocket fire towards Israel over recent days as well as in previous rounds of fighting. Islamic Jihad is an Iranian-backed militant group allied with Hamas, which rules the enclave.

Air raid sirens sounded in areas of southern Israel around the Gaza Strip, and Reuters images showed rockets intercepted by Israeli air defences in the night sky. Israeli jets hit targets including a mortar post in the northern part of the enclave.

The Israeli military said it has attacked 158 targets in Gaza while at least 523 rockets were launched towards Israel this week, and 380 crossed into Israel but air defences intercepted 96 per cent of those that threatened to hit targets.