By Michael Bristow
BBC News, Beijing
Ethnic Tibetan regions of China are under heavy security
Two Tibetans have been executed for their involvement in riots in Tibet last year, the Chinese government has confirmed.
They are thought to be the first executions in relation to the unrest, which left at least 22 people dead.
There are reports that two more Tibetans have been executed, but that has not been confirmed.
China also spoke out against interference following criticism of the executions from a UK minister.
News that two Tibetans had been executed first came last week from Gu Chu Sum, an organisation based in India that helps former political prisoners.
Pro-Tibetan groups and the Tibetan government-in-exile named the men who died as Lobsang Gyaltsen and Loyak, who went by just one name.
Chinese foreign ministry spokesman Ma Zhaoxu confirmed at a regular press briefing on Tuesday that "two criminals" had been executed, although he did not give their names.
He said: "I would like to point out that China's judicial authorities handled the cases according to the law."
Mr Ma said the two fully expressed their views through their lawyers at a public trial and had been given interpreters.
The two men were sentenced to death in April for starting fires in riots that gripped the Tibetan capital Lhasa in March 2008.
Lobsang Gyaltsen was accused of starting fires in two clothes stores that killed a shop owner. Loyak is said to have set fire to a motorbike store, causing the deaths of five people.
British foreign office minister Ivan Lewis, who visited Tibet in September, condemned the executions last week.
"We respect China's right to bring those responsible for the violence in Tibet last year to justice," said Mr Lewis. "But the UK opposes the death penalty in all circumstances, and we have consistently raised our concerns about lack of due process in these cases in particular."
Mr Ma responded at the press briefing by saying that no one had the right to interfere in China's legal process.
The unrest broke out last year when peaceful demonstrations turned into riots in Lhasa. China says 22 innocent civilians died in the violence.
Protests and violence quickly spread to other Tibetan areas across China, in the provinces of Qinghai, Gansu and Sichuan.
Pro-Tibetan groups and the Tibetan government-in-exile, base in Dharamsala in India, say that scores of Tibetans were killed in the unrest and subsequent government crackdown.
Security is still reported to be tight in Tibetan areas, more than a year-and-a-half after the most serious unrest involving Tibetans in two decades.