By Samanthi Dissanayake
Tamils have been fleeing the fighting in the north and east of the island
Aid agencies in Sri Lanka are assessing their future strategy after the government said it could no longer guarantee the safety of aid workers in rebel-held territory in the north.
There are 11 international agencies operating in Wanni district and aid workers have expressed concern about the future for civilians displaced by the fighting.
"We are very worried about civilians in the area. Over the last few months, people have been pushed further north and we have had difficulties reaching them as it is," one aid director, who wished to remain anonymous, told the BBC.
"Food and shelter is an issue. If people are pushed into Mullaitivu district, the situation will deteriorate even further. We don't know who will look after them," he said.
The UN has already said it will begin withdrawing staff from Wanni this week.
But a spokesperson for the International Committee for the Red Cross said it was "committed to stay to help people, whether in LTTE [rebel]-controlled or government-controlled areas." It says it is currently in discussions to try to ensure that staff safety can be guaranteed.
All agencies are in talks with the government on how best to maintain aid operations. Some are considering moving staff from Wanni to Vavuniya district and agencies may then be reliant on the government to distribute aid.
"We are having discussions with the ministry of disaster management to see how well we can complement the government distribution mechanism," Mr Firzan Hashim , deputy director of the Consortium of Humanitarian Agencies (CHA), said.
"The government is very confident that the existing government agents and arms can work."
But others say the humanitarian outlook remains bleak for those displaced civilians left in Wanni.
"The most urgent need for people is food. The refugees have no shelter, homes or money and they cannot buy anything. They need shelter and now it is raining and more rain is expected," the aid agency director said.
Many of the displaced have found shelter in schools but they will have to be put into temporary shelters as schools reopen.
"The government can provide basic food but people also need utensils for cooking, temporary toilets, which are what agencies can provide and we have to do that through the government now, " Mr Hisham said.
However, concern is not confined to people's humanitarian requirements. The aid director said that as the war escalates, security is a genuine issue. Some of his workers have already experienced shelling and bombing in the areas they operate in.
Many civilians have had to move several times because of the fighting and it is widely expected that people will continue to move as the frontline advances. Some will simply move deeper into LTTE-held territory.
"I think there are certain people in the government who have a genuine desire not to harm civilians. But the problem is that when an area becomes small civilians get pushed in - you cannot distinguish who is a civilian and who is not," the aid director said.
The situation is further complicated by reports that the local staff of agencies may not be issued with passes by the LTTE to leave the area, even if the agencies want to take them out, according to Mr Hisham.
"We want to secure these local staff by proposing that they can work with the government agents to provide assistance to civilians - so we can assure their security and they can be helpful to the humanitarian cause as well," he said.