Uruguay has ordered the repatriation of five of its peacekeepers from Haiti, accused of involvement in the sexual assault of a teenage boy.
The head of Uruguay's naval contingent in Haiti has also been relieved of his post over the incident.
\Uruguay acted after a video clip appeared on the internet, which purported to show the abuse.
It is the latest controversy involving UN peacekeepers in Haiti.
The Uruguayan military said it was taking "severe and exemplary measures" to deal with the allegations, and that it would apply the maximum penalty if the accused men were found guilty.
Uruguay, which has 1,200 military personnel in the UN mission in Haiti, was prompted to act after a video clip of the alleged abuse appeared on the internet.
In the short clip, which was recorded on a telephone, several men in uniform are heard to laugh as they hold down a teenage boy on a bed during what appears to be a sexual assault at a UN base in southern Haiti.
A spokeswoman for the United Nations mission in Haiti (Minustah) told the BBC that it had immediately ordered an investigation by its military police.
"The United Nations has a zero tolerance policy towards misbehaviour, or sexual exploitation or abuse," Eliane Nabaa said.
"We have taken these allegations extremely seriously, and if the allegations are proved, the perpetrators must be brought to justice."
Last week, Uruguay's Defence Minister, Eleuterio Fernandez Huidobro, ordered an urgent investigation into the allegations of what he called "aberrant acts" by peacekeepers in Haiti.
Haitian officials are conducting their own inquiry, led by an investigating magistrate.(BBC)