The incidents occurred Thursday in the Tibetan prefecture of Aba in a rugged area of China’s Sichuan province, the London-based group Free Tibet said in a statement.
It added that the fate of the pair was not known, but a Tibetan Buddhist monk in the area told AFP by phone that both had died.
Free Tibet said Chinese security forces were en route to the town of Barma, where the incident took place in front of a Tibetan Buddhist monastery.
Local authorities either refused to comment when contacted by AFP or calls went unanswered.
A total of 34 Tibetans, many of them Buddhist monks and nuns, are now reported to have set themselves on fire since the start of 2011 in protest at what they see as Chinese repression of their culture.
Many of them have reportedly died as a result of severe burns.
Free Tibet identified those involved in Thursday’s protest as Sonam and Choephak Kyap, saying they were laypeople in their 20s.
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