Gaza City, Gaza Strip ? Israel widened its deadliest-ever air offensive against Gaza’s Hamas rulers Sunday, pounding smuggling tunnels and government strongholds, sending more tanks and artillery toward the Gaza border and activating thousands of reservists for a possible ground invasion.

Israeli leaders said they would press ahead with the Gaza campaign, despite enraged protests across the Arab world and Syria’s decision to break off indirect peace talks with the Jewish state. Israel’s foreign minister said the goal was to halt Gaza rocket fire on Israel for good, but not to reoccupy the territory.

Border wall breach

With the two-day death toll nearing 300 on Sunday, crowds of Gazans breached the border wall with Egypt to escape the chaos. Egyptian forces, some firing in the air, tried to push them back into Gaza and an official said one border guard was killed.

Hamas, in turn, fired rockets deeper than ever into Israel, near the Israeli port city of Ashdod.

Yet Hamas leaders were forced into hiding, most of the dead were from the Hamas security forces, and Israel’s military intelligence chief said Hamas’ ability to fire rockets had been reduced by 50 percent. Indeed, Hamas rockets fire dropped off sharply, from more than 130 on Saturday to just over 20 on Sunday. Still, Hamas continues to command some 20,000 fighters.

Israel’s bombings consisted of some 300 airstrikes since midday Saturday. After nightfall, Israeli aircraft attacked a building in the Jebaliya refugee camp next to Gaza City, killing a 14-month-old baby, a man and two women, Gaza Health Ministry official Dr. Moaiya Hassanain said. Israeli aircraft also bombed the Islamic University and government compound in Gaza City, centers of Hamas power, and the house next to the residence of Hamas Prime Minister Ismail Haniyeh in a Gaza City refugee camp. Haniyeh, in hiding, was not home.

‘War between states’

Shlomo Brom, a former senior Israeli military official, said it was the deadliest force ever used in decades of Israeli-Palestinian fighting. “Since Hamas took over Gaza (in June 2007), it has become a war between two states, and in war between states, more force is used,” he said.

European leaders called on Israel and Hamas to end the bloodshed. The White House was mum about the situation in Gaza on Sunday after speaking out expansively on Saturday, blaming Hamas for provoking Israel’s retaliatory strikes.

In the most dramatic attacks Sunday, warplanes struck dozens of smuggling tunnels under the Gaza-Egypt border, cutting off a lifeline that had supplied Hamas with weapons and Gaza with commercial goods. The influx of goods had helped Hamas defy an 18-month blockade of Gaza by Israel and Egypt, and was key to propping up its rule.

Stretched resources

Gaza’s nine hospitals were overwhelmed. Hassanain, who keeps a record for the Gaza Health Ministry, said more than 290 people were killed over two days and more than 800 wounded.

The Palestinian Center for Human Rights said it had counted 251 dead by midday Sunday, and that among them were 20 children under the age of 16 and nine women.

In Jerusalem, Israel’s Cabinet approved a call-up of 6,500 reserve soldiers. Israel has doubled the number of troops on the Gaza border since Saturday and also deployed an artillery battery. It was not clear, though, whether the deployment was meant to pressure Hamas or whether Israel is determined to send ground troops.

Israeli Prime Minister Ehud Olmert said it was unclear when the operation would end but told his Cabinet it was “liable to last longer than we are able to foresee at this time.”

Since Israel’s withdrawal from Gaza in 2005, after 38 years of full military occupation, Israeli forces have repeatedly returned to the territory to hunt militants. However, Israel has shied away from retaking the entire strip, for fear of getting bogged down in urban warfare.

Hundreds of thousands of Israelis live in cities and towns in Gaza rocket range, and life slowed in some of the communities. Schools in communities in a 12-mile radius from Gaza were ordered to remain closed beyond the weeklong Jewish holiday of Hanukkah, which ends today.