About a dozen pro-Tibet protesters jumped the walls of a building housing the offices of the United Nations in Nepal on Friday, seeking UN intervention following the unrest in the Himalayan region.

Tibetans living in Nepal have been protesting almost every day since the trouble began this month in the Tibetan capital Lhasa and hundreds, including nuns and monks, were detained to break up their march to the U.N. offices.

On Friday, about a dozen Tibetan students carrying placards quietly scaled the walls of the U.N. complex and began protesting.

"They are sitting inside with their placards," a witness said from inside the compound in an upmarket area of Kathmandu.

Some of the protesters were in school uniforms and were carrying "free Tibet" placards.

"Stop cultural genocide in Tibet," another read.

U.N. officials could not be immediately reached for comments.

Outside the U.N. building police detained dozens of other protesters some 20 minutes after the students jumped the wall, a second witness said.

Nepal, home to more than 20,000 Tibetans who have been living there since they fled the Himalayan region in 1959, does not permit any anti-China activities by the exiles.

Beijing is also poor Nepal's key trading partner and a major aid donor to its economic development.