Israeli warplanes continued to pummel Hamas targets in the Gaza Strip on Sunday. The air campaign has killed nearly 300 Palestinians so far, with most of the dead being Hamas policemen.

As Israeli reservists start to mobilize, many fear the start of a much larger offensive against Hamas militants.

The air campaign has killed nearly 300 Palestinians so far, with most of the dead being Hamas policemen. [Xinhua]

Israeli warplanes resumed another round of air strikes on Sunday night, targeting security and police installations belonging to Hamas.

Earlier in the day, the Israeli air force attacked the Seraya compound in downtown Gaza, a major symbol of the Hamas authority.

Israel has also expanded its campaign to southern Gaza, bombing some 40 smuggling tunnels running under the border with Egypt.

Its aircraft also targeted a tanker truck carrying supplies that had been smuggled into Gaza through those tunnels. The resulting explosion set off a blaze that spread to about a dozen nearby houses.

Meanwhile, Israel's Cabinet has authorized a call-up of at least 6,500 reserve soldiers, a move that suggests plans to expand the offensive.

Officials say the campaign is a direct response to almost daily rocket and mortar attacks on Israel.

Tzipi Livni, Israel Foreign Minister, said, "Since Hamas is using the civilian population and is acting and targeting Israel from civilian population centers, we call the civilians to leave these places. We are trying to make all the efforts in order to target only terrorists and Hamas headquarters and places. But unfortunately in a war like any war sometimes also civilians pays the price."