Israeli tanks have pushed deep into Gaza City, prompting fierce exchanges of gunfire with fighters of the Palestinian militant group Hamas. The UN's relief agency, Unrwa, says part of its HQ in the city is on fire after being shelled by the Israelis. Secretary General Ban Ki-Moon expressed outrage at the attack, and said Israel had told him it was a grave mistake. Efforts to reach a truce continue, with Israel's head negotiator in Cairo to discuss an Egyptian ceasefire plan. Hamas said the talks had made progress, but did not elaborate. Speaking to reporters on the Israel-Gaza border, Unrwa spokesman Christopher Gunness said three of the agency's employees were hurt in the attack.

Six seriously injured Palestinian children have been flown to Belgium from the war-torn Gaza Strip for treatment in Brussels hospitals. The children were airlifted on a Belgian military plane, which brought them from El-Arish, an Egyptian town about 60km (37 miles) from Gaza. Belgian media say the children's ages range from two and a half to 18 years. Each child is accompanied by a parent. More than 200 Belgians have offered to accommodate the parents, reports say

Residents spoke of heavy machine-gun fire as Israeli troops fought Hamas gunmen near Gaza City. Israel said it launched 60 air strikes overnight. The fighting has reportedly killed nearly 1,000 Gazans and 13 Israelis. Diplomatic moves to end the crisis continue, with UN head Ban Ki-moon urging an immediate ceasefire after talks in Egypt with President Mubarak.