UNITED NATIONS — Four UN peacekeepers from Bangladesh have been sent home and 13 other peacekeepers serving in southern Sudan are under investigation for alleged serious misconduct including sexual exploitation and abuse, the United Nations said yesterday.The Bangladeshis were repatriated several months ago “and a case will be pursued in front of a national jurisdiction,” UN spokeswoman Michele Montas said.

“We have different allegations against them — not all of them are sexual allegations.”

“As of today, there are 13 ongoing investigations regarding allegations of serious misconduct including sexual exploitation and abuse,” Montas added. The nationalities of the 13 peacekeepers under investigation were not disclosed.

The UN announcement comes on the heels of a report in a British newspaper alleging that UN personnel in Juba, the capital of southern Sudan, were involved in sexual exploitation and abuse.

The Daily Telegraph cited interviews with more than 20 children who alleged they were raped and sexually abused. It also cited an internal report by the UN children’s agency, but Montas said that document focused on sexual abuse by the Sudanese military, not UN peacekeepers.

The paper reported the alleged abuse began two years ago when the UN Mission in southern Sudan, known as UNMIS, arrived to help maintain peace in the region after a more than two-decade civil war.

Montas said the United Nations is still trying to determine whether the allegations against the four Bangladeshis and the 13 investigations now being conducted by the UN in southern Sudan involve the same cases raised by the Daily Telegraph — or whether the paper has uncovered new cases.

A 14-year-old boy identified only as Jonas told the newspaper “I was sitting by the river the first time it happened.” A 13-year-old boy told the paper he was lured to a UN car with the offer of cash, abused and dumped by the side of a road.

Montas said Wednesday that Secretary-General Ban Ki-moon was “deeply concerned” by the report, and she reiterated the UN’s determination “to end sexual abuse by peacekeepers.”

“The UN standard on this issue is clear — zero tolerance, meaning zero complacency and zero impunity,” she said.

The Office of Internal Oversight Services, the UN’s internal watchdog known as OIOS, has a team permanently based in Sudan. It investigates all allegations of abuse involving the more than 11,000 peacekeepers, police and international civilian staff in the country. OIOS also has teams in Congo, Liberia and Haiti, where the UN has other large peacekeeping operations.

While allegations of abuse have dogged peacekeeping missions since their inception over 50 years ago, the issue was thrust into the spotlight after the United Nations found in early 2005 that peacekeepers in Congo had sex with Congolese women and girls, usually in exchange for food or money.

Jordan’s UN Ambassador Prince Zeid al Hussein wrote a report several months later that described the UN military arm as deeply flawed and recommended withholding the salaries of the guilty and requiring nations to pursue legal action against perpetrators.

It said abuses had been reported in missions ranging from Bosnia and Kosovo to Cambodia, East Timor, West Africa and Congo.

The UN peacekeeping department instituted a new code of conduct for peacekeepers and new training for officers and all UN personnel, and it reinforced messages against sexual abuse.

UN Assistant Secretary-General for Peacekeeping Jane Holl Lute said Tuesday night the UN would ascertain the facts about the paper’s allegations and take action if necessary.

“We won’t be complacent and there will be no impunity to the full extent of the UN’s authority,” she said.

Lute, who served in the US Army for 16 years, said vigilance on this matter has to be “a constant factor of life when you’re rotating through 200,000 troops in as diverse environments as we do.”