Tens of thousands of people, on the run because of fighting between Sri Lankan government troops and the LTTE, have no safe passage, the Red Cross said Friday.
Aid workers and diplomats have expressed growing concern over the fate of the civilians trapped in LTTE-controlled territory in the northeast after months of fighting, especially with increasing reports of civilian casualties.
The International Committee of the Red Cross (ICRC) said it was "extremely concerned" that the warring parties had not agreed on a safe route for civilians since January 9.
"For the last five days for example, there has been no aid that has reached this population at all because of the fighting," Paul Castella, the ICRC's head of delegation, told Al Jazeera.
"And its not just about aid or assistance, but also about healthcare for the sick and the wounded," Castella said. "As you know, a number of hospitals had to be evacuated because of the moving frontline."
"This has put at risk the lives of patients who cannot receive suitable treatment on the spot and therefore need to be transferred to Vavuniya Hospital, in government-controlled territory," the ICRC said in a statement.
It did not say what type of treatment the patients needed and if they had been hurt in the fighting.
The ICRC said there had been a "massive displacement" of civilians - many of them having already been forced to move numerous times - who were increasingly seeking safety away from the war zone.
"Repeated displacements, often involving the loss of their personal belongings, have taken a toll," Castella was quoted by AFP as saying.
Castella said fighting had prevented relief supplies from reaching the refugees.
"Tens of thousands of displaced civilians are concentrated in an area so small that there are serious concerns for their physical safety and living conditions, in particular in terms of hygiene," ICRC said.
"Families heading westward in search of safety are encountering other families moving eastward with the same aim," Castella said.
The ICRC is among the few international relief agencies allowed to operate in LTTE-held areas. The Sri Lankan government ordered most of the others out, citing security concerns.
Aid groups say about 230,000 people are trapped in an area of no more than 330 square km (127 square miles), and that they are under increasing attack from air strikes and shelling.
Foreign journalists are prevented from entering the conflict zone, but Al Jazeera said it had exclusive pictures showing civilians fleeing the fighting as buildings burn and craters from heavy shelling pockmark the earth.
"We lost everything, our property and all," one fleeing civilian told Al Jazeera. "It was the same at the last place we were staying, we lost everything there too."
"We don't have any property now, we have lost everything. We are now worse than before, we don't have anything to eat."
Aid agencies say at least 30 people are being either killed or wounded daily in the violence, and getting food and emergency medical supplies to the area is also becoming impossible.
But the Sri Lankan military denies shelling civilians. President Mahinda Rajapaksa has said he had ordered the army to avoid all civilian casualties - even if it means slowing down the offensive.
The Sri Lankan government and rights groups have accused the LTTE of forcing Tamil civilians to stay in the war zone to be conscripts or labourers. The LTTE denies that and even the military admits that in the past civilians have largely ignored government appeals for them to cross into military-held areas.
Selvamalar Ayadurai, who runs an aid organisation helping civilians in Sri Lanka's north, says the term genocide may be justified.
"They use the term genocide - it may be right because the definition for genocide is a systematic and planned destruction of a social, racial or political group. So this is the destruction of a racial group, which are the Tamils of northern Sri Lanka," she told Al Jazeera.
