Police in Nepal broke up a protest by 200 Tibetan refugees and monks near the offices of the United Nations on Monday by beating them with bamboo sticks and arresting 40. The refugees demonstrating in Kathmandu were demanding that the UN investigate the recent crackdown in Tibet by Chinese authorities. Chanting "China, stop killings in Tibet. UN, we want justice," the protesters were marching to UN headquarters when police stopped them about 100 meters from the office and snatched their banners. When the Tibetans tried to break through the police line and push ahead, officers charged with batons and arrested several protesters, dragging them to trucks and vans to be taken to police stations. Nepal has said it will not allow protests against any "friendly nation," including China. International human rights groups and the UN have already criticized Nepal on the use of force in the past few days on protests around Kathmandu involving some of the thousands of Tibetan refugees living in the country. The UN's human rights office last week said it was concerned about the police use of excessive of force on peaceful protests and it was seeking clarification from the Nepali government about the instructions given to the police. New York-based Human Rights Watch also urged Nepal to stop doing "Beijing's bidding" and end its crackdown on Tibetan exiles protesting against China. The groups said last week that Nepal "should cease arbitrary arrests and detentions, harassment, and the use of excessive force to silence Tibetan protesters, activists and journalists." Nepal's government has good relations with neighboring China, and has not issued any statements on Beijing's crackdown on anti-Chinese protests in Tibet. Nepal's border with China in the Himalayas is a key route for Tibetans fleeing Chinese rule in the region. Thousands of Tibetan refugees live with relatives in Nepal or in camps funded by aid groups. Most of the refugees eventually move to India, where Tibet's government-in-exile and its spiritual leader, the Dalai Lama, are based.