A Tibetan monk who set himself on fire this week in a southwestern town that has become a flashpoint for protests against Chinese rule has died, an exile group said on Thursday.

The man, named as Tashi and in his 20s, died of his injuries a day after he and another monk set light to themselves on Monday, according to the India-based Tibetan Centre for Human Rights and Democracy.

The other monk, named as Langtag, died on Monday after the protest in southwestern Sichaun province's Aba county, which prompted clashes between residents and police.

The two monks were from Aba's Kirti monastery, which has been under extremely tight security since a monk self-immolated in March 2011, kicking off the recent wave of such protests.

Since then nearly 50 ethnic Tibetans, many of them monks and nuns, have set themselves on fire to protest at what they say is religious repression.

China has accused the Dalai Lama -- who fled Tibet following a failed uprising against Chinese rule in 1959 and is vilified as a "separatist" by Communist authorities -- of encouraging the protests.

The Dalai Lama has himself condemned self-immolations, which many Buddhists believe are contrary to their faith, but blamed them on hardline Chinese rule of Tibetan-populated areas.

Many Tibetans in China accuse the government of enacting religious repression and eroding their culture, as the country's majority Han ethnic group increasingly moves into historically Tibetan areas.

But China rejects this, saying Tibetans enjoy religious freedom and pointing to huge ongoing investment, which it says has brought modernisation and a better standard of living.

Kirti monastery and Barkham Hospital where Tashi died could not be reached for comment, while the Aba propaganda department declined to comment.