Nepalese police arrested 11 people in Kathmandu on suspicion of "anti-China activities" on Sunday morning, the anniversary of the 1959 rebellion against China's rule in Tibet.
"Some of the people we arrested were Tibetan but we have not interrogated all of them yet," police spokesman Uttam Subedi told AFP.
Nepal, home to around 20,000 Tibetans, is under intense pressure from Beijing over the exiles, and has repeatedly said it will not tolerate what it calls "anti-China activities".
On February 13 a Tibetan monk doused himself in petrol in a Kathmandu restaurant and set himself on fire, becoming the 100th self-immolation bid in a wave of protests against Chinese rule since 2009.
In the lead-up to Sunday's 54th anniversary of the Tibet uprising, the Nepal government re-exerted its security efforts.
Home ministry spokesman Shanker Koirala told local journalists last week that the government was making "necessary security arrangements in areas deemed sensitive, to foil any untoward incidents."
Tibetan anger at Beijing's control simmered for decades and erupted into violent riots against Chinese rule in the Tibet regional capital Lhasa and adjacent areas in March 2008.
Speaking with AFP last week, Tibetan activists in Kathmandu said they had planned subdued protests this year, citing increased security presence around their community.
"The community in Nepal needs space in which to peacefully express their anguish and their solidarity, particularly at a moment as significant as the March 10 anniversary," said Kate Saunders of the US-based International Campaign for Tibet.
Since 2009, 107 Tibetans have set themselves on fire to protest at China's rule and at least 90 have died.