Police in the small landlocked Himalayan kingdom, sandwiched between India and China, have reportedly issued such a threat to the Tibetans, whose protests this month of Chinese rule of their homeland have been spreading in countries with large Tibetan exile population.

Nepalese authorities reportedly arrested about 300 Tibetan protesters this week.

The Voice of America reported Nepalese riot police surrounded a temple, refugee camp and nunnery to prevent Tibetan monks and others from leaving the premises.

Human Rights Watch said police pre-emptively detained monks and others while moving around Kathmandu.

"They were saying that they will take everybody inside the truck and then they will reach to the border of Tibet and they will hand over all the people to the Chinese soldiers," one exile was quoted as saying.

The VOA report said Nepal supports the "one China policy," in which China claims Tibet and Taiwan as parts of its territory.