The true death toll may not be known for some time
And the level of destruction is becoming more evident. Our correspondent, Jeremy Cooke, who was among a small group of journalists escorted into the camp by Israeli soldiers, described a scene of utter devastation.
Rene Aquarone, spokesman for the UN Relief and Works Agency, (UNRWA) which looks after Palestinians in refugee camps, said: "We need access.
"We tried to distribute food yesterday (Monday) but the authorisation to enter came so late that the truck could only get into the camp at six o'clock in the evening - and then we were not given permission to unload and had to leave."
A Spokeswomen for the World Health Organisation (WHO) and Unicef also said that the agencies were unable to deliver food and medical aid to needy people who had been under curfew in Jenin for more than a week.
The WHO is worried about the risk of diseases such as cholera and diphtheria breaking out in the camps due to lack of running water and medical supplies.
'War crime'
Our correspondent said any buildings still standing were marked with gunfire.
On the streets tanks and armoured personnel carriers and Israeli foot patrols were still operating.
Most of the camp's 13,000 inhabitants fled the incursion, but some are now returning to shattered or deserted homes.
"My house is destroyed. I'm now staying at my brother's," said Mohammed Ballaf, freed after being rounded up with hundreds of people by Israeli forces.
He said he had yet to see his wife and four children, who fled the ferocious fighting for the nearby city of Jenin.
"My house can be repaired, but it will cost a lot of money. Everything is burnt inside," he told Reuters.
Senior Palestinian official Nabil Shaath said on Tuesday that Israel's alleged "massacre" of hundreds of Palestinians at Jenin refugee camp included between 60 and 70 summary executions.
He told a Cyprus-hosted UN conference on Middle East peace: "The massacre in Jenin is really horrible. It is a war crime."
But the row over the number of dead could carry on for some time because of the level of devastation.
Bodies gathered
Our correspondent said it could take days, perhaps even weeks to sort through the wreckage.
The Israeli Supreme Court has insisted the Red Cross be allowed to monitor the gathering of the corpses - against the wishes of the Israeli army.
But ambulances from UNRWA and the Red Cross were only able briefly to collect eight bodies from the camp late on Monday.
Mr Aquarone said they would need more help to get to other bodies.
"We're going to need heavy lifting equipment to wrest them from the rubble - and to look for survivors."