last two weeks.
The spurt in cases of protest suicides is being interpreted as an attempt by ethnic Tibetans to focus attention on what they perceive as Beijing's hardline rule at a time when new leaders have taken over the Communist Party of China (CPC).
More than 70 have self-immolated in ethnically Tibetan areas since February 2009; most have died.
The International Campaign for Tibet (ICT) said hundreds of Tibetans were surrounded by troops as they attended Chagmo Kyi's cremation at a site normally used for the cremation of monks and lamas.
The group said the woman had frequently driven between Tongren and Xining, the provincial capital, and was also a farmer.
London-based Free Tibet also reported the self-immolation.
"There is a heavy security presence in Rongwo. At least 20 trucks, each with 20 armed police standing in the back, are stationed at intersections throughout the town, plain clothes police are common, and there are reports of cars, each with about five government officials inside, positioned every twenty paces along most streets, monitoring the population. Rongwo has been the scene of several huge protests this year, as well as a growing number of self-immolations," the group said in a statement.
The Chinese government was yet to confirm the incident till Sunday evening.
Last week, Tibetan delegates to the just concluded 18th National Congress of the CPC ruled out allowing international observers to visit Tibet to investigate human rights after the UN made an appeal that independent monitors should be allowed to do so.
According to ICT, there were no indicators of future policy change on Tibet or other 'ethnic minority' issues given the new configuration of the 25-member Politburo Central Committee, which ranks below the seven-member Standing Committee.
"There has been a decrease in the number of Tibetans in the Central Committees of the Party, which are lower-ranking than the Politburo. For the past few Party Congresses, there were at least two Tibetans in the 200-plus members of the Committee, but this time only one is included, Pema Thinley, the current head of the TAR government. There are, however, four Tibetans as Alternate Members, which is the largest number to date," ICT said in a statement.