Aid agencies who have been operating in Sri Lanka for decades say the upsurge in violence in the north and the east in recent weeks is hampering relief work and putting aid workers in peril.
There have been frequent clashes between rebels and army
Nearly 80 Sri Lankan security personnel and about 50 civilians have been killed in the last two months, prompting fears that another full-scale war is not far off.
The worsening security situation has made it next to impossible for ordinary citizens to carry on with their daily life.
And now aid agencies are complaining about facing difficulties in moving freely around areas hit by the December 2004 tsunami because of security fears.
"It is hard to meet people in the evening. The security situation does not allow us to meet affected civilians after office hours," says Abdel Fattah Burkhan of the aid agency, FORUT, in the eastern town of Batticaloa.
Whenever there is a mine explosion or a grenade attack, civilians and bystanders often get caught in the crossfire.
Demining operations have been badly hit by the violence
Ordinary people often get beaten up and some may well end up in custody on suspicion of involvement in the incident.
In addition people suspected of conniving with the government forces also get targeted.
As a result, fear grips towns like Jaffna and Trincomalee where people are too scared to come out of their homes after nightfall.
As for aid workers, they may not be directly threatened by the security forces or the Tamil Tiger rebels - but they are afraid of ending up in the wrong place at the wrong time.
If relief work gets scaled down or abandoned because of the security situation, the ramifications for those most in need could be severe.
Relief and rehabilitation
Nearly half a million people were made homeless by the tsunami.
More than 65,000 houses were completely destroyed posing a massive reconstruction challenge for the government and the aid agencies.
Sri Lanka received pledges of nearly $3bn of international assistance.
But the government and the rebels failed to establish a Tsunami Joint Mechanism to distribute aid money to the Tamil-dominated north and east.
Many of the tsunami survivors are still in temporary shelters
With the government and the rebels unable to resolve their differences over aid, relief organisations and some government agencies have shouldered more responsibilities, especially in tsunami-affected Tamil areas.
Even so, more than a year after the disaster it is estimated that only about 10% of those who lost their homes in the tsunami have now got permanent houses.
At this rate, reconstruction work will take many years to complete.
Apart from the tsunami victims, aid agencies are still working to rehabilitate more than half a million Sri Lankans previously displaced because of the ethnic conflict.
Now, thousands more people have been displaced in the fresh wave of violence in the north and the east.
When five Tamil students were killed in Trincomalee in early January the whole town came to a standstill for many days.
Fearing trouble, some aid agencies temporarily halted their work.
"We suspended our operations in Trincomalee for five days as we were unable to travel to the field to work with the communities," says Nick Osborne, Sri Lanka country director of Care International.
While the violence hampers relief work, some fear that escalating tensions could possibly force many NGOs without expertise of working in conflict areas either to shut down or to drastically scale down their operations.
Aid agencies say they are encouraged by the recent agreement between the government and the rebels to discuss a fragile four-year-old ceasefire.
But some aid agencies say although they may not withdraw completely, they have already drawn up evacuation plans if the situation worsens.
If that happens, those most in need will be the worst hit.