Colombo - An estimated 6,000 civilians have moved into a "safe zone" declared by the government in northern Sri Lanka as fighting between security forces and Tamil rebels continued, a government minister said Wednesday.

Defence spokesman Minister Keheliya Rakbukwella told journalists that civilians have started to move into the safe zone, covering an area of three villages in Mullaitivu district, 370 kilometres north-east of the capital.

The civilians who have moved into the government-declared safe zone are part of the government-estimated 150,000 civilians trapped in the rebels' remaining territory. But UN aid agencies and the ICRC estimate that the number of civilians in the area is around 250,000.

Minister Rambukwella claimed the transfer by the ICRC of some 300 patients from rebel-controlled areas to government-controlled areas had to be aborted on Tuesday because the rebels refused to grant permission for them to leave.

On Tuesday Sri Lanka reassured India that it will respect the safe zones declared by the security forces to minimize the effects of the conflict on Tamil civilians.

The assurance was given when President Mahinda Rajapaksa met with visiting Indian External Affairs (Foreign) Minister Pranab Mukherjee on Tuesday.

The International Committee of the Red Cross Wednesday expressed concern about the civilians caught in the conflict.

"People are being caught in the crossfire, hospitals and ambulances have been hit by shelling and several aid workers have been injured while evacuating the wounded. The violence is preventing the ICRC from operating in the region," said Jacques de Maio, ICRC head of operations for South Asia in Geneva in a statement released in Colombo.

"The terrified population is in need of protection, medical care and basic assistance, according to the ICRC," the statement said. "When the dust settles, we may see countless victims and a terrible humanitarian situation, unless civilians are protected and international humanitarian law is respected in all circumstances."

"The ICRC urgently appeals to both sides to allow and facilitate the safe and voluntary movement of civilians out of the combat zone", the statement added.

The ICRC said it was determined to remain in the northern Wanni region as long as possible, but said "the parties must respect its presence and its work."

The ICRC is the only humanitarian agency remaining in the area.

Meanwhile, fighting continued in Mullaitivu district, which is the last stronghold of the rebels of the Liberation Tigers of Tamil Eelam
(LTTE) as the military declared that the rebels were now confined to an area of less than 300 square kilometres.

Government troops have captured vast areas formerly held by the rebels in the northern and eastern parts of the country in their operations launched since August 2006 and have now entered what they describe as the final phase of the offensive. (dpa)