Hamas Gaza Israel
Smoke and flames are seen following what police said was an Israeli air strike in Rafah in the southern Gaza Strip. Reuters

The Palestinian death toll from Israeli air strikes on the occupied enclave of Gaza has risen to 100, according to Palestinian medical sources.

Israel has conducted more than 1,000 airstrikes against Gaza targets, killing dozens of civilians and over 20 children in what the Israel Defence Forces (IDF) claim is retaliation for rockets fired by Hamas at major Israeli cities.

The Palestinian health ministry says that, in addition to those killed, 675 people have been injured in the Israeli strikes.

Since midnight, Hamas fired 44 rockets into Israel, with 11 intercepted by the Iron Dome system, while Israel targeted 159 terror targets in Gaza, according to the IDF.

According to a Reuters correspondent in Gaza, an Israeli air strike killed five people without warning while they slept overnight while a second strike killed a girl in Rafah.

In Israel, three people were injured when a rocket struck a petrol station in Ashdod, Israeli officials said.

In northern Israel, two rockets were fired across the shared Lebanese border and Israel retaliated with fire towards the source in southern Lebanon, according to an Israeli military spokesman.

President of the Palestinian Authority Mahmoud Abbas suggested that Israel was to launch a ground offensive "in hours" before US President Barack Obama intervened to offer to mediate a ceasefire between Israel and Hamas.

In the call to Israeli Prime Minister Benjamin Netanyahu, Obama said: "The United States remains prepared to facilitate a cessation of hostilities, including a return to the November 2012 ceasefire agreement."

He "expressed concern about the risk of further escalation and emphasised the need for all sides to do everything they can to protect the lives of civilians and restore calm".

Egypt's foreign ministry has condemned Israel's "excessive and unnecessary use of military force leading to the death of innocent civilians" while Turkish Prime Minister Recep Tayyip Erdogan also condemned their Gaza strikes.

"You have to end this oppression. As long as it does not end, a normalising of ties between Turkey and Israel is not possible."