Updated

Three men who survived a harrowing odyssey at sea that saw dozens die of thirst and starvation on a boat fleeing Libya have been found in Tunisia, the U.N. refugee agency said Friday.

Melissa Fleming, a spokeswoman for the U.N. High Commissioner for Refugees, said the Ethiopian men were discovered in the Shousha refugee camp in Tunisia early Thursday.

The men's account to aid workers confirms London's Guardian newspaper report that the boat carrying sub-Saharan migrants from Libya to Italy encountered military units who refused to help, Fleming told reporters in Geneva.

"The refugee said that military vessels twice passed their boat without stopping, and that a military helicopter dropped food and water onto the boat at some point during the journey," said Fleming. "The first boat refused their request to board. The second only took photos," she said, citing one of the witnesses.

The man was unable to identify where the vessels came from, but NATO has vigorously denied that any of its units were involved.

Sixty-three of the 72 people on board died, including all the women and children. The survivors were arrested by pro-Gadhafi forces after their boat came ashore in Libya, but managed to flee again, this time overland to Tunisia.

UNHCR estimates that at least 1,200 people have perished trying to flee Libya in unseaworthy boats since fighting broke out between rebels and forces loyal to Moammar Gadhafi. The agency said earlier this week that almost 600 people are believed to have died in a single incident on May 6, when a boat capsized shortly after leaving Tripoli harbor.