Israeli warplanes pressing one of Israel’s deadliest assaults ever on Palestinian militants widened their sights yesterday, dropping bombs on smuggling tunnels that are a major weapons pipeline for the Gaza Strip’s Islamic Hamas rulers.

Crowds of Gazans, backed by a bulldozer, breached the border wall with Egypt amid the ensuing chaos. Syria, reflecting the rage in the Arab world over Israel’s aerial onslaught, announced it would break off indirect peace talks with the Jewish state.

Earlier, Israel’s Cabinet authorised the military to call up 6,500 reserves soldiers for a possible ground invasion. Israel’s offensive against Gaza rocket squads who have been barraging southern Israel for years has been carried out exclusively from the air since it began on Saturday.

The air strikes, which initially targeted Hamas security compounds, killed more than 280 Palestinians and wounded hundreds more in its first 24 hours, said Gaza health official Dr Moaiya Hassanain. A Palestinian human rights group said among 251 dead it counted, 20 were children under 16 and nine were women.

The Palestinian Centre for Human Rights said it was difficult to keep an exact count because of chaos at the hospitals, and difficulty in identifying some of the dismembered bodies.

The civilian casualties included a 15-year-old boy who died in southern Gaza yesterday in an attack on a greenhouse near the border. At least 644 people were wounded, Hassanain said.

Militants launched more than 20 rockets and mortars at Israeli border communities. The number of attacks was down sharply from a day earlier, indicating the Israeli airstrikes had taken a stiff toll. Israel’s head of military intelligence told Israel’s Cabinet that Hamas’ ability to fire rockets had been reduced by 50%.

Israeli Prime Minister Ehud Olmert said it was unclear when the operation would end. The situation in southern Israel “is liable to last longer than we are able to foresee at this time,” he told his Cabinet.

The carnage has inflamed Arab public opinion. A Syrian official said Damascus would suspend indirect peace talks with Israel, begun earlier this year, over the Gaza attacks.

Israel’s foreign minister Tzipi Livni told the US news show, Meet the Press, that Israel launched its strike because Gaza’s Hamas rulers were smuggling weapons and building up “a small army”.

But, she added, “Our goal is not to reoccupy the Gaza Strip”.

In New York, the UN Security Council called on Israel and the Palestinians to immediately halt all violence and military activities.

US Ambassador Zalmay Khalilzad, Israel’s closest ally on the Security Council, said "the key issue here was not to point a finger at Israel. The key issue was to urge all parties to end the violence and address the humanitarian needs of the people of Gaza."

Streets were empty in Gaza City as most residents stayed home, fearing more airstrikes. A few lined up to buy bread outside two bakeries. Schools were shut for a three-day mourning period the Gaza government declared Saturday for the campaign’s dead.

Aircraft struck one of Hamas’ main security compounds in Gaza City — a major symbol of the group’s authority. Health officials said four people were killed and 25 wounded. A column of black smoke towered from the building and some inmates of the compound’s prison fled after the missiles struck.

One prisoner trapped under the rubble, his face bloodied, waved his hand in the hope of being rescued. Two other prisoners helped a bleeding friend walk through the debris.

Since the campaign began, around 150 rockets and mortars have bombarded southern Israel, the military said.

In Ashkelon, a city of 120,000 people about 11 miles from Gaza, bustling sidewalks immediately emptied after a rocket fell downtown.

Store Clerk Elvira Taberbobsky, 36, stepped outside after one rocket struck only to have a second explode right in front of her.

"I flew backwards. I couldn’t hear anything for a few seconds, and then all of a sudden I saw holes in my pants and blood streaming down my pants," she said.</>