Israeli forces intensify Gaza offensive

Gaza: Israeli forces tightened their hold around the city of Gaza on Tuesday and Israel's top general said "there is still work" ahead against Hamas in an 18-day-old offensive that has killed more than 900 Palestinians.

Explosions and heavy machinegun fire echoed through the city of 500,000 after Israeli tanks drew closer to its densely populated centre but did not enter, local residents said.

Medical workers said 18 Palestinian gunmen, most of them members of the Islamist Hamas group that rules the Gaza Strip, and three civilians were killed in fighting in the territory.

Israeli aircraft attacked 60 targets, including tunnels used by Gaza militants to smuggle arms across the border from Egypt, weapons-making sites and Hamas command posts, the army said. Two rockets hit Beersheba in southern Israel, causing no casualties.

Human rights groups have reported shortages of vital supplies including water, in the Gaza Strip. A fuel shortage has brought frequent power blackouts.

Israel has permitted almost daily truck shipments of food and medicine. But in a new report, Human Rights Watch said Israel's daily three-hour break in attacks to facilitate the supply of humanitarian aid to Gazans was "woefully insufficient."

Palestinian medical officials said at least 933 people in the Gaza Strip have been killed and nearly 4,000 wounded since Israel began its offensive on December 27. The health minister in Gaza's Hamas-run government said close to 400 of those were women and children.