Israel stepped up air strikes in the Gaza Strip after Hamas and other militant groups rebuffed Palestinian President Mahmoud Abbas's call for a halt to cross-border rocket attacks on the Jewish state.

One of the air strikes hit a car carrying Hamas militants. The militants escaped unharmed but at least two people nearby were injured in the blast, witnesses said. Other Israeli air strikes targeted Hamas's financial network, the army said.

Mr Abbas, whose secular Fatah faction shares a shaky two-month-old unity government with the ruling Hamas Islamists, had hoped to convince militants to stop rocket attacks against Israel as part of a renewed ceasefire with the Jewish state.

The Islamist group and others said they would only consider stopping rocket attacks if Israel first called off all of its military operations in Gaza and the occupied West Bank.

Israeli air strikes over the last eight days have killed at least 35 Palestinians.