The Palestinian death toll in the Gaza conflict climbed to more than 1,000 today after nearly three weeks of intensive Israeli bombing and fighting on the ground.

So far, 1,010 Palestinians have been killed, among them 315 children and 95 women, Dr Moawiya Hassanein, the head of Gaza's medical emergency services, told the Guardian. The number of injured after 19 days of fighting stood at 4,700, he said.

As Israeli troops fought on the outskirts of Gaza City after another night of heavy bombing and shelling, diplomatic efforts to end the conflict intensified, with the secretary-general of the UN, Ban Ki-moon, in Cairo for urgent talks. He is calling for an immediate ceasefire.

With the death toll rising, Bolivia's president, Evo Morales, said his country had cut diplomatic relations with Israel. He called for Israeli leaders to face charges at the international criminal court.

The head of the international committee of the Red Cross described the situation in Gaza as "shocking" after visiting a hospital in the territory.

"I saw this dramatic humanitarian situation. There's an increasing number of women and children being wounded and going to hospitals," Jakob Kellenberger said later in Jerusalem, the AFP news agency reported.

"It is shocking. It hurts when you see these wounded people and the types of wounds they have. And I think that the number of people coming to these hospitals is increasing," he said. Kellenberger, who called on both sides to stop targeting civilians, demanded better access for medical teams within Gaza, saying the daily three-hour pause in Israeli operations was not sufficient.

Ban described the toll on civilians in the conflict as "intolerable". He called for "an immediate end to violence in Gaza, and then to the Israeli military offensive and a halt to rocket attacks by Hamas".

His demand followed a meeting with the Egyptian president, Hosni Mubarak. The UN chief is also scheduled to travel to Jordan, Israel, the West Bank, Turkey, Lebanon, Syria and Kuwait, although not Gaza itself.

As well as the Palestinian death toll, 13 Israelis have been killed, including three civilians. At least 35,000 Palestinians are holed up in UN schools operating as emergency shelters. Tens of thousands more are staying with relatives or friends.

About two-thirds of the territory's 1.5 million people have no electricity; the rest have only an intermittent supply, according to the UN.

There was more heavy fighting in northern Gaza today and around the edges of Gaza City, from where Israeli troops have mounted raids to within a mile of the city centre. Early today, the old Gaza city hall, a former court building, was destroyed in an air strike which damaged many shops in the nearby market.

Israel's military said it had hit 60 sites overnight, including the police headquarters in Gaza City that had been hit on the first day of the operation, as well as rocket launching sites, weapons stores and 35 smuggling tunnels under the border with Egypt. Six Israeli soldiers were injured.

Three rockets fired from Lebanon landed in northern Israel in the second such attack since Israeli forces launched their Gaza offensive. Police said the rockets landed in open areas and there were no reports of damage or injuries. People in northern Israel were advised to head to bomb shelters. Reports from Lebanon said five rockets were fired but that two fell short. Israel's military responded with artillery fire towards the firing sites.

Four rockets were fired on northern Israel last Thursday. Hezbollah denied responsibility and speculation focused on small Palestinian groups in Lebanon.

Rifts among Israel's leaders over the conflict are appearing to deepen. The defence minister, Ehud Barak, is pressing for a one-week halt to the fighting to allow in humanitarian aid, according to a report today in the Ha'aretz newspaper. Barak believes the 19-day offensive has bolstered Israel's deterrent power and believes continuing the fight would bring "only operational complications and casualties", the paper said.

"Barak is proposing the IDF [Israel Defence Forces] cease its fire, hold its positions and keep the reservists under arms, and thus negotiate with Egypt and the United States on an arrangement that would prevent arms smuggling into the strip," it said.

Barak fears that when Barack Obama assumes the US presidency on Tuesday he will demand an immediate Israeli ceasefire. Another risk was a tougher UN security council resolution – a resolution last week calling for a ceasefire was ignored as "unworkable" by Israel.