Earlier, Israel rejected mounting international pressure to suspend its devastating air offensive against Gaza.

Israeli warplanes again struck at tunnels allegedly used to smuggle food, fuel and weapons from Egypt into Gaza.

In Gaza City, powerful airstrikes continued to shake high-rise apartment buildings and shower streets with broken glass and pulverised concrete.

Israeli navy ships also fired at Hamas positions along the coastline.

Meanwhile more than two dozens Hamas rockets and mortar shells were fired by mid-day on Wednesday, including five that hit in and around the major southern Israeli city of Beersheba. One reportedly hit an empty school.

Diplomatic action moved into high gear, set in motion by the scale of destruction in Gaza since Israel unleashed its campaign on Saturday, and a death toll that Gaza officials now put at 390, and more than 2,000 wounded.

Meanwhile, four Israelis have been killed by rocket fire from Gaza, including three civilians.

Calls for an immediate ceasefire have also come from the US, the European Union, the UN and Russia.

Protests against the Israeli action have also taken place in major cities around the world.