Fears are growing over the plight of civilians caught in fighting between Sri Lanka’s army and Tamil Tiger rebels.
The United Nations says it will send a humanitarian team to the war zone to help people leave, however, the government has rejected calls for more aid agencies to be allowed in claiming it is too dangerous.
More than 6,000 people have been killed and many more injured during the last three months as the military advances.
But with conventional victory thought to be close, Sri Lanka has rejected calls for another truce after its two-day holiday pause last week was spurned by guerrillas.
Since Monday more than 100,00 people have fled the tiny northern coastal strip, a 12 sq km area, but UN officials believe the rebels are preventing others from escaping.
Catherine Bragg, Assistant Secretary-General for Humanitarian Affairs said: “We continue to have reports that heavy weaponry is being used. We continue to have reports that the LTTE (Liberation Tigers of Tamil Eelam) is preventing people from leaving that area and using the human shields.”
The rebels have been fighting for 25 years to create an independent homeland for ethnic minority Tamils, who say they have faced decades of marginalisation by governments controlled by ethnic Sinhalese.