KATHMANDU, Nepal (CNN) -- Nepalese authorities Thursday detained at least 650 Tibetan exiles protesting against China's policies in the province ahead of this weekend's Olympic torch relay in Tibet, security officials in Kathmandu said.
A protester is grabbed by Nepalese police during a demonstration in Kathmandu.
Police also arrested and charged three local Tibetan community leaders with organizing the protest, after seizing them from their homes Thursday morning.
It is the largest single-day round-up of Tibetan protesters in Nepal since the demonstrations broke out in March following China's bloody crackdown on protesters in Tibet.
It is also the first time that Nepalese authorities have charged any Tibetan exiles in connection with the protests.
Nepalese police forcefully dragged some of the protesters to awaiting vans and drove them to police stations across the capital. Tibetan exile groups said 900 protesters were detained Thursday.
Authorities said the three arrested leaders -- two women and a man -- were responsible for the near-daily protests since March and will be held for 90 days under Nepal's public security act.
"They have been arrested for damaging the diplomatic relations between Nepal and China," said civilian security officer Jaya Mukunda Khanal.
The two women arrested and charged for organizing the protests were Ngwang Sangmo, president of Tibetan Women's Association, and Tashi Dolma, vice president of the association.
Also charged was Kelsang Chung, director of the Tibetan Reception Center, which helps Tibetan refugees in Nepal emigrate to India, where the Tibetan spiritual leader, the Dalai Lama, lives in exile.
While they are the first Tibetan exiles formally arrested, protesters have previously been detained and released hours later.
The crackdown comes days before the Olympic torch relay in Tibet.
The torch relay wrapped up in China's Xinjiang Uygur Autonomous Region on Wednesday, and will continue in Tibet's capital of Lhasa on Saturday, according to China's Olympic Web site.