Colombo  - Sri Lankan President Mahinda Rajapaksa on Wednesday invited UN Secretary General Ban Ki-moon to visit government-run camps to see for himself how tens of thousands of civilians are being treated after being driven from areas where the government is battling Tamil rebels.

Rajapaksa made the invitation when Ban phoned him Tuesday evening to discuss the plight of civilians as the president faced criticism over allegations that government troops shelled civilian areas in northern Sri Lanka.

The conversation came as local and international aid groups expressed concerns over the fate of an estimated 50,000 civilians, members of the Tamil ethnic minority, who are trapped in a narrow, rebel-held strip of land on the coast of north-eastern Sri Lanka. The government has accused the rebel Liberation Tigers of Tamil Eelam
(LTTE) of holding them as human shields.

The military is trying to gain control of the area, the last held by the LTTE.

More than 188,000 people who fled the rebel-controlled area live in camps put up by the government, but access to foreign aid workers and journalists has been restricted.

Rajapaksa told Ban that if he visited he also "would be able to make a better assessment of the conditions faced by the Tamil civilians still held hostage by the LTTE," a statement said.

However, it remained unclear whether the secretary general would be allowed into the conflict area after previous requests were rejected by the government, which cited security reasons.

The government has said its troops are in the last phase of crushing the LTTE, which has been fighting for an independent homeland for Tamils for more than 25 years. (dpa)