A Sri Lankan minister quit his post on Friday and vowed to pursue an anti-UN hunger strike, as UN chief Ban Ki-moon recalled his top envoy in Colombo and closed the world body's besieged offices there.
Housing Minister Wimal Weerawansa had begun a "death fast" on Thursday outside the compound of the UN Development Programme (UNDP) to protest a UN probe into alleged rights abuses committed in the final stages of Sri Lanka's decades-long civil war.
Weerawansa said on Friday he was resigning his cabinet seat to deflect criticism that his agitation was being orchestrated by the government.
"I have no intention of causing embarrassment for the government," he said in a letter to President Mahinda Rajapakse. "I choose to resign from cabinet and keep up my struggle."
Several government ministers visited Weerawansa, who is camped outside the UNDP office, to express solidarity with his stance.
Demonstrators have held angry protests outside the compound for the last four days, prompting Ban on Thursday to recall his chief representative in Sri Lanka, Neil Buhne, and close the UNDP's regional centre.
"The minister is adamant. He will keep up the fast," Weerawansa's spokesman Anuruddha Bandara told AFP.
"A doctor saw the minister and said he can last only about five days without food and water," Bandara added. Opposition MPs have dismissed the hunger strike by the 40-year-old as a stunt.
The minister's supporters marched to the Russian embassy Friday to seek Moscow's support in quashing the UN probe into reports of abuses by government troops in the final months of the conflict with Tamil Tiger separatists.
Russia's foreign ministry had criticised Ban for not conferring with the UN Security Council or the General Assembly before convening the investigating panel.
The Tiger guerrillas were defeated in May 2009 and the United Nations has said that at least 7,000 ethnic Tamil civilians were killed in the military's final offensive.
Many observers view the UN panel, headed by Marzuki Darusman, a former Indonesian attorney general, as a precursor to a full-blown war crimes investigation.
The demonstrators in Colombo have promised to keep up their agitation until Ban withdraws the probe.
The protests, which saw UNDP staff held hostage in their offices for nearly seven hours on the first day, have been condemned by the United States, as well as Ban himself.
Through his spokesman, the UN secretary-general urged Sri Lanka to "live up to its responsibilities towards the United Nations as host country".
"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 organised and led by a cabinet minister of the government," Ban's spokesman said.
Diplomatic sources said both local and expatriate staff working for other UN agencies in Colombo had been asked to maintain a low-profile.
"They have been told to stay indoors because of the anti-UN sentiments orchestrated by groups linked to the government," a diplomat close to the UN said.
The private-run media in Sri Lanka has criticised the government for encouraging the protests and warned that it is pushing the country towards international isolation.
"By puppeteering the (NFF) allies for mischief, Sri Lanka has only gone to distance itself from the independent, moderate countries in the international community," the Daily Mirror said in an editorial headlined: "Theatrics of a death fast."
There was no immediate reaction from the Sri Lankan government to the UN decision to close the office in Colombo.