Hamas's leader in exile has said that his group will not consider a Gaza ceasefire until Israel ends its 15-day-old military offensive and opens border crossings.
'Let Israel pull out first, let the aggression stop first, let the crossings open and then people can look into the issue of calm,' said Khaled Meshaal in a televised speech in Damascus.
Israeli tanks and planes have bombarded Gaza and Hamas militants have fired rockets into Israel today.
Both sides have been ignoring a truce window and defying international efforts to stop the conflict.
An Israeli tank shell killed eight Palestinians in Jabalya, a refugee camp in the north of Gaza, and an air strike killed a woman in nearby Beit Lahiya, Palestinian medics said.
All of those killed in Jabalya were believed to be men from the same family. The deaths raised the Palestinian toll to at least 821, according to the Hamas-run Health Ministry in Gaza.
13 Israelis have been killed: 10 soldiers and three civilians hit in rocket fire.
The fighting continued even during a three-hour ceasefire window that Israel has established in recent days to allow humanitarian aid into Gaza to sustain the 1.5m people living there.
As Israeli tanks advanced in northern Gaza and aircraft hit targets across the coastal strip, Hamas rockets hit Ashkelon, 20 km north of Gaza, wounding three Israelis.
UN hopes to resume aid flows
Concerned about the deepening humanitarian impact of the war, with more than half Gaza's population dependent on UN food assistance, the UN said it hoped to resume full aid distribution after receiving Israeli assurances that its staff would not be harmed. A UN driver was killed on Thursday.
Israel has pressed on with its offensive despite a UN Security Council resolution calling for a ceasefire and Egyptian-European efforts at mediation, saying it is intent on stopping Hamas rocket fire. Hamas too has ignored calls for a halt to hostilities, firing at least eight rockets at Israel.
'Israel is determined to deal with this matter until its positive conclusion, so that there is no terrorism in Gaza against Israel,' Rafi Eitan, a member of Israel's security cabinet, told Israel Radio.
At least two Israeli tank shells hit northern Gaza immediately after the 1100-1400 GMT humanitarian truce window opened, residents said. Off the coast, Israeli ships trawled the water with their machineguns trained on northern Gaza.
Israeli tanks advanced from the north towards the city of Gaza, creeping in on the large refugee camp of Jabalya, home to around 100,000 people.
In an attempt to breathe life into a faltering Egyptian-led mediation effort, Palestinian President Mahmoud Abbas, whose Fatah party is a political foe of Hamas, met Egyptian President Hosni Mubarak for talks in Cairo.
They discussed the possible deployment of international forces along the Gaza-Egypt border under any ceasefire deal, but Abbas said they should be in Gaza itself, not along the border.
Egypt initiative thought in trouble
Privately, diplomats believe the Egyptian initiative, also sponsored by French President Nicolas Sarkozy, is in trouble, even if Israel has said talks over the proposal will continue and Hamas has sent representatives to Cairo.
'There is a growing sense that the Egyptian-French plan is not going to work,' a senior European diplomat told wire services.
European and Israeli diplomats said Egypt was objecting to proposals that foreign troops and technicians be stationed on its 15-km border with Gaza to prevent arms smuggling.
Instead, diplomats said, Egypt was ready to accept technical assistance for its own forces on the border. Israel says the Egyptians have failed in the past to prevent Hamas building up an arsenal of hundreds of Soviet-designed Katyusha missiles.
Likewise, the UN Security Council resolution late on Thursday calling for an immediate and durable ceasefire appears to have found no traction with either Israel or Hamas.
Israeli Prime Minister Ehud Olmert dismissed it as unworkable and Hamas officials in the Gaza Strip said they objected to it because they had not been consulted.
The US, which abstained in the UN vote, offered further public support for Israel's military goals.
'This situation will not improve until Hamas stops lobbing rockets into Israel,' White House spokesman Scott Stanzel said.
He said US President George W Bush had expressed concern to Mr Olmert about the humanitarian situation and the loss of civilian lives during the Israeli assault on the Gaza Strip.
With the Palestinian civilian death toll already in the hundreds, Israeli actions have drawn denunciations from the Red Cross, UN agencies and Arab and European governments.
UN sources said Israel was also stepping up operations in the West Bank, detaining Palestinian suspects in rising numbers.
Hamas wants any ceasefire deal to include the ending of Israel's crippling economic blockade of Gaza and the withdrawal of all Israeli forces from the territory, from which Israel withdrew in 2005 after a 38-year occupation.
Israel's key demands are for a complete halt to Hamas rocket fire and for international guarantees to stop the group rearming via smuggling tunnels under the border with Egypt.
RTE