China has blamed "trained separatists" for a wave of unrest in Tibetan-inhabited areas last week that left at least two people dead and dozens injured, state press reported Wednesday.

The southwestern province of Sichuan -- which has big populations of ethnic Tibetans, many of whom complain of religious repression and a lack of freedom -- was rocked by three violent clashes last week.

Rights groups say security forces shot dead peaceful protesters in each of the incidents but China has acknowledged only two of them, and says they were triggered by a violent crowd of demonstrators.

"Initial evidence showed that the riots and assaults were well planned beforehand and instigated by trained separatists against the country," the official China Daily newspaper said, citing the Sichuan government.

It said protesters attacked police stations with stones and molotov cocktails, prompting the police to take action and "defend themselves".

Chinese authorities have barred foreign journalists from going to the affected areas, making independent attempts to verify the situation there near impossible.

"The riots were serious crimes plotted by Tibetan separatist forces in and outside of China," the English-language Global Times said, also citing the Sichuan government.

"Local police were forced to open fire, killing two rioters and wounding several others."

Officials at the Sichuan information office refused to comment when contacted by AFP.

Chinese-language media has made scant mention of last week's violence in Tibetan-inhabited areas, in an indication of official concern the unrest will spread.

According to the English-language China Daily, 24 police officers and firemen were injured in the violence.

Tibetans have long chafed under Chinese rule, saying they suffer religious repression and government surveillance, and that their culture is gradually being eroded by an influx of majority Han Chinese into the areas they live in.

Beijing, though, insists that Tibetans enjoy freedom of religious belief and says their lives have been made better by huge ongoing investment into Tibetan-inhabited areas.