Tearfund, CAFOD and World Vision are among the leading UK relief agencies expressing alarm at the escalation of hostilities in north and east Sri Lanka which has seen a further 210,000 people displaced from their homes in the last seven months - almost half the number that were forced to leave their homes following the tsunami.

Other agencies deeply concerned by the situation are ActionAid, CARE International, Merlin, Save the Children and Oxfam.

The post-tsunami aid and reconstruction efforts have been severely hampered by the devastating impact of conflict and the restriction of movements in certain parts of the country, developments which have created further substantial humanitarian needs.

Controlled and restricted access for aid agencies, meanwhile, has resulted in serious delays to building projects while materials and workers are unable to enter some areas.

Tearfund also reported a growing disparity between the extent and progress of reconstruction in the north and south of the island.

In the north east, which has seen an alarming escalation of military activity between the Liberation Tigers of Tamil Eelam (LTTE) and Sri Lankan government forces, up to half a million people have been cut off on Jaffna peninsula.

The situation is a particularly painful experience for so many who already suffered intense trauma when the tsunami hit in December 2004. Now many of those victims have found themselves displaced for a second time due to the fighting.

According to CARE International's programme targets, only 10 per cent of post-tsunami house reconstruction has been completed in the conflict-hit north of the island compared to nearly 90 per cent in the relatively stable south.

Devastatingly, one third of the 210,000 people newly displaced by the conflict are children, while prices in Jaffna have skyrocketed with basic food items like rice and sugar costing up to four or five times more than they did three months ago.

Roshan Mendis is the Director of a Sri Lankan agency funded by Tearfund operating throughout the country. He says that there is a growing climate of fear and anxiety among the population on the east coast that crosses ethnic and religious divides.

"The people that suffered so acutely two years ago have been thrown into uncertainty for a second time," says Roshan. "Our teams are trying to bring relief and restore the lives of families, but increasingly our operations and logistics are restricted. Relief agencies must be allowed to get through, if we are to avoid a major and needless humanitarian catastrophe."

Sally Austin from CARE International adds, "Not only are we desperately keen to fulfil the commitments we've made to the communities who were affected by the tsunami but we're also witnessing the dire humanitarian consequences of the ongoing hostilities. Safety and reliable access to all parts of the island are critical for us to move ahead with reconstruction and humanitarian relief."

Some areas have suffered major disruptions to basic services that were previously being restored. Electricity was quite recently cut to only two hours a day in some areas, schools have intermittently been forced to close, and there is a shortage of medical supplies that is having a knock on impact on health and nutrition.

"We have to remain accountable to both beneficiaries and the British public," says Save the Children's Sri Lanka-based Advocacy and Communications Director, Phil Esmonde. "We must ensure that generous donations given to the DEC tsunami appeal are focussed on reconstruction. But equally agencies can't ignore this conflict and the hundreds of thousands displaced."