An official two-day ceasefire in Sri Lanka which ended on Wednesday has not helped to end the suffering of around 100,000 civilians trapped in the conflict zone.
According to media reports, John Holmes, the United Nations (UN) under secretary general for humanitarian affairs, said that the 48-hour break in hostilities to allow aid in and civilians out was "inadequate".
As fighting intensifies in Sri Lanka, Amnesty International has called on the Sri Lankan government and the Liberation Tigers of Tamil Eelam (LTTE) to declare an immediate temporary humanitarian truce, so that desperate civilians can escape to safety.
The UK, France and India are also said to have called on Sri Lanka to offer another truce to the LTTE.
The UN has reported that the Tamil Tiger fighters killed six civilians trying to flee the conflict zone during the ceasefire. The organization also said in March that more than 2,800 civilians had been killed and more than 7,000 injured since the beginning of the year.
Civilians still trapped in the Wanni in the north-eastern part of Sri Lanka, require urgent humanitarian aid as reports emerge that food and medical supplies are running low.
All reports from the conflict zone are impossible to verify as the area has, in effect, been sealed off by the Sri Lankan government, denying access to aid workers and independent human rights observers.
Amnesty International contacted two medical workers at the main hospital in the no-fire zone, who described a scene of chaos, with the hospital running out of anaesthetic, surgical blades and basic medications.
One medical worker reported that 92 injured civilians had been brought to the hospital on Thursday and that fighting was intensifying. Another medical worker reported 75 casualties had arrived at the hospital with gunshot wounds on Wednesday and that at least 12 civilians were killed.
"The human misery and desperation is rising and has now reached alarming proportion," said Sam Zarifi, Amnesty International's Asia Pacific Director.
"We call on all parties to the conflict to make sure that civilians are not put further at risk and for international observers such as the UN to ensure that a real ceasefire is implemented.
"To avoid further bloodshed the Tamil Tigers must let civilians move to areas of safety and the government must extend the ceasefire."