Chinese Premier Wen Jiabao has blamed the Dalai Lama and his followers for instigating the violent protests in Tibet.
At a news conference in Beijing Tuesday, Mr. Wen said rioters caused heavy loss of life and the government acted with extreme restraint in putting down the protests.
He said claims from the Dalai Lama that China is committing cultural genocide in Tibet are nothing but lies.
Chinese authorities say 13 "innocent civilians" died in Friday's riots in the Tibetan capital Lhasa.
The Indian-based exile Tibetan government says at least 80 people were killed. It says it fears renewed violence in Tibet after the passing of a deadline Chinese authorities gave protesters to surrender.
Witnesses have reported a heavy military presence on the streets of Lhasa. Security personnel have also been conducting house-to-house searches for participants in last week's demonstrations.
An editorial published Monday in the city's official newspaper, the Tibet Daily, warned of harsh security actions against what it called separatist activities.
Chinese media have published more details of alleged violence carried out by Tibetan rioters Friday against Han Chinese and Chinese Muslims. Official media also carried reports criticizing Western media coverage of the events, and defended China's response to what the media called criminal activities.
The Chinese media did not carry details of last week's peaceful protests in Lhasa that preceded Friday's rioting, security forces response to the rioting, or news of Tibetan protests in Tibetan communities in nearby provinces.
Details of recent events in Tibet are difficult to verify because Chinese authorities have not permitted foreign journalists to provide coverage.
Human rights groups reported that protests against Chinese rule spread Monday into an increasing number of Tibetan communities in the Tibet Autonomous Region. Tibetan students at the Central University for Nationalities in Beijing staged a candle-light vigil.
China has controlled Tibet since 1951. Tibet's spiritual leader, the Dalai Lama, and thousands of his followers fled from Tibet to India in 1959, during a failed revolt against Chinese rule. China denounces the Dalai Lama as a crusader for independence, but he says he has campaigned for nothing more than true autonomy for his homeland.
Some information for this report provided by AP, AFP and Reuters.