COLOMBO  – The United Nations closed its office in Sri Lanka and recalled its representative Thursday, following angry public protests over a UN probe into alleged war crimes committed by government forces.

Secretary General Ban Ki-moon ordered his main representative in Sri Lanka, Neil Buhne, to return to New York after rowdy scenes which began outside the UN compound in Colombo on Tuesday.

"The secretary-general finds it unacceptable that the Sri Lankan authorities have failed to prevent the disruption of the normal functioning of the United Nations offices in Colombo as a result of unruly protests organized and led by a cabinet minister of the government," Ban's spokesman said in New York.

Through his spokesman, Ban urged Sri Lanka "to live up to its responsibilities towards the United Nations as host country, so as to ensure continuation of the vital work of the organization to assist the people of Sri Lanka without any further hindrance."

A Sri Lankan cabinet minister leading the anti-UN demonstration said the protest would continue until the UN withdrew a panel set up to investigate alleged rights abuses during nearly four decade of fighting between the Colombo government and Tamil Tiger separatists.

Many observers view the panel, headed by Marzuki Darusman, a former Indonesian attorney general, as a precursor to a full-blown war crimes investigation.

Ban had recalled Buhne and shut down the regional centre of the United Nations Development Programme in Colombo, the spokesman's statement said.

The UN chief named a three-member panel last month to advise on "accountability issues" during the war between government forces and the Tamil Tiger separatists, which ended in May last year.

There was no immediate reaction from the Sri Lankan government to the UN's decision to close the office, but it came hours after External Affairs Minister Gamini Lakshman Peiris said he hoped the crisis would be resolved soon.

Peiris's colleague, Housing Minister Wimal Weerawansa, meanwhile kept up his "death fast" outside the UN offices while hundreds of his supporters gathered around him.

Demonstrators did not block the entrance of the UN offices, but employees had been ordered to remain at home during the day since Wednesday, local UN officials said.

"We will keep up the action until the UN panel is withdrawn," said Weerawansa, who is leading the protest with tacit support from the government.

He called on Sri Lankans abroad to stage similar protests outside UN offices around the world.

UN employees in Colombo were holed up inside their compound for seven hours Tuesday until police moved in to allow them to leave.

The Sri Lankan government issued a statement backing the demonstrators' wish to continue protesting until the UN "revisits the matter of the panel".

But the island's main opposition asked the government to end the confrontation with the United Nations and cooperate with any probe.

Ban visited Sri Lanka soon after the fighting ended and Colombo agreed with him to address allegations of excesses committed by troops during the final months of fighting.

The Tiger guerrillas were defeated in May 2009 after decades of conflict, and the United Nations has said that at least 7,000 ethnic Tamil civilians were killed in the first four months of last year.

A US spokesman on Thursday said Washington believes that Colombo would benefit from working with the United Nations on the probe.

"We feel like it's in Sri Lanka's best interest to accept these people and their expert advice that's offered in good faith," State Department spokesman Mark Toner told reporters.(AFP)