Apr 30, New York: The United Nations would continue to push the Sri Lankan government for a "humanitarian pause" in the fighting and give the UN and other aid workers sufficient time for humanitarian assistance, a top UN official said on Wednesday.

Addressing a press conference at the UN Headquarters in New York, Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator, Sir John Homes who just returned from a three-day visit to Sri Lanka said he had discussions with President Mahinda Rajapaksa and other key government ministers for a pause in military operations.

However, Sri Lankan officials denied the request on the grounds that the LTTE rebels would exploit the lull to regroup militarily and continue their armed resistance, he said.

"But we continue to ask for that, not least to get in more humanitarian aid, to get in more food," Holmes said.

The UN official said the government must exercise restraint particularly the use of heavy weapons to minimize the civilian casualties.

Referring to the Sri Lankan government's assurance on Monday that their security forces will end the use of heavy caliber guns, combat aircraft, and aerial weapons which could cause civilian causalities, Holmes said "I hope very much that that promise will be respected."

Holmes also urged the LTTE to let the civilians who they are holding against their will go, let them out to safety and preferably lay down their arms and surrender to prevent further fighting and further loss of life.

Describing the situation in the welfare centers in Vavuniya, Holmes said although far from satisfactory the basics facilities are there for the people to at least survive.

"We will be able to continue to improve their conditions as we go along," he said.

According to the UN official approximately 175,000 civilians including the 110,000 arrived last week are housed in these centers.

The most serious concern is the congestion in the camps and the UN has asked the Sri Lankan government for more land to build more camps.

The United Nations High Commissioner for Refugees (UNHCR) had set up 4,500 family-sized tents for the IDPs, Holmes said.

Responding to a question regarding access to screening centers Holmes said he visited the main screening point in Omanthai, where UNHCR had a presence, but he was not allowed to talk to people during the screening process. Holmes said the ICRC is allowed outside the screening point to ensure safe passage to the camps for civilians.

The UN was pressing Sri Lankan officials for full access so it could assess the situation, as well as allegations of people being pre-screened by the Sri Lankan army prior to arriving at the centres, Holmes added.