Five criminal suspects have been detained over two arson attacks in which 10 people died during the Lhasa riots and have confessed their guilt, said an official with the Chinese Ministry of Public Security Monday.

The ministry's spokesperson Shan Huimin briefed the public on the two arson cases at a press conference.

Three suspects have been detained for an arson attack at a shop named Yishion at 2:30 p.m. March 14 in which five female sales assistants were burnt to death.

In another case, two people were detained over an arson attack in a motorbike shop at around 10 p.m. March 15, which caused the deaths of five victims including an eight-month old boy and his parents.

Riots erupted in Lhasa on March 14 when rioters set fire to and looted public facilities, buildings and shops. The violence has 242 police officers injured, according to Shan.

Shan said facts had proved that the March 14 riot was by no means a "peaceful demonstration" and "peaceful protest", but a severe violent criminal incident.

The criminal sabotages were well-organized, premeditated and an outcome of overseas forces instigating domestic separatists to resort to violence.

Their ulterior motive was to disturb the Beijing Olympic Games, destroy the peace and stability and split the country.