FRANKFURT- U.N. Secretary General Ban Ki-moon will call on Sri Lanka on Saturday to allow full access to nearly 300,000 refugees who fled during the final months of the war against Tamil Tiger rebels, U.N. officials said.

Ban, due to arrive in Sri Lanka later on Friday, plans to meet the country's leaders and visit at least one of the refugee camps where people are being held in conditions that human rights groups have criticized as unacceptable.

A senior U.N. official traveling with Ban's delegation told reporters on Friday the secretary-general would press the government to ensure that members of the Tamil minority have equal rights in post-war Sri Lanka.

Having won the 26-year-old war earlier this week, the government needed to win the peace and settle this conflict so it doesn't go back to a guerrilla war, said the official, speaking on condition of anonymity.

The official said U.N. aid agencies still lacked full access to the refugees and that the government had hampered the delivery of aid by banning the use of motor vehicles by U.N. officials or aid workers from non-governmental organizations.

If we don't have free access to (the refugees), we can't help, he said, adding some camps where the U.N. had been denied full access were built with U.N. funds and other assistance.

U.N. diplomats say the government intends to screen camp inmates for rebels who might have succeeded in disguising themselves as refugees.

INVESTIGATION DEMAND

New York-based Human Rights Watch sent a letter to Ban urging him to push for an international inquiry into possible human rights and humanitarian law violations during the final months of the war.

More than 7,000 civilians were killed and many more were wounded in these months, according to U.N. figures.

The senior U.N. official stopped short of endorsing an investigation but said accountability for any such violations would be an important issue.

He said the Geneva-based U.N. Human Rights Council would be meeting soon to discuss Sri Lanka and might want to launch an investigation.

This victory was won at a very high price, said the official, adding there would be a certain amount of lingering bitterness as a result.

Ban and other senior U.N. officials repeatedly criticized the government and the Liberation Tigers of Tamil Eelam during the final months of the war, saying the actions of both had resulted in unnecessary deaths of thousands of Sri Lankans trapped in the conflict zone.

Ban