Israel kept up air strikes and artillery fire on the Gaza Strip Monday despite diplomatic efforts to halt the bloodshed, as its offensive entered the seventh day.

Aircraft struck three training facilities of Hamas's military wing, the Ezzedine Al Qassam Brigades, around the coastal territory, but caused no casualties, medics and eyewitnesses said.

They also hit buildings in Gaza City, Deir el-Balah in the southern part of the strip, and in the northern town of Jabaliya, injuring an unspecified number of people.

There was shelling reported in Beit Lahiya, in the far north of the strip, where Israel had earlier warned residents of an impending assault.

Israel also moved against Hamas in the occupied West Bank, arresting at least five of the movement's lawmakers in Nablus and Jenin, Palestinian security officials told AFP.

UN chief Ban Ki-moon said "too many" Palestinian civilians have been killed, as the Palestinian death toll from the punishing Israeli campaign hit 172 with another 1,230 people wounded.

Ban also urged Israel to scrap plans for a potentially devastating ground offensive, fears of which have sent Gazans fleeing from the north.

Israeli army radio quoted security sources "at the most senior level" as saying that there were "four channels for attempts to reach a ceasefire -- Qatar, the Palestinian Authority, the Americans and the Egyptians."

"According to those sources the Egyptian channel is the strongest, the most significant and the one that draws together all those channels of mediation," the station's military affairs reporter said.

US Secretary of State John Kerry phoned Netanyahu to renew a US offer to help mediate a truce and he "highlighted the US concern about escalating tensions on the ground," a senior State Department official said.

Kerry also said that he was engaged with regional leaders "to help to stop the rocket fire so calm can be restored and civilian casualties prevented".

Palestinian president Mahmud Abbas said he would ask Ban to "put the State of Palestine under the UN international protection system" in order to address the violence in Gaza.

As the death toll rose, the Gaza-based Palestinian Centre for Human Rights said most of the victims were civilians, putting their number at more than 130, among them 35 children and 26 women.

Rocket fire from Syria, Lebanon

A rocket fired from Syria hit the Israeli-occupied sector of the Golan heights but landed on empty ground, causing no casualties.

Israel responded with artillery fire at Syrian army positions, the Israeli military said.

Four rockets fired from southern Lebanon struck northern Israel early Monday, Lebanese security sources said.

No casualties were reported in Israel and the army responded with artillery fire.

An AFP correspondent in southern Lebanon reported more than 30 shells were fired, but there was no information yet on casualties. Agencies