The two boys, aged 12 and 14, admitted to playing with matches on the night of the fire and then leaving their room next to that of the two girls who died, police spokesman Liu Wei told a news conference.

The fire broke out at the three-star Catic Plaza Hotel at around 11:00 p.m. on Saturday, killing the girls, aged 12 and 17, and sparking concern in Hong Kong over safety standards for study tours in China that are becoming increasingly popular.

"After investigation by fire experts and painstaking work, experts confirmed the fire sprang from human cause. Therefore, the police have concluded that the two boys, Deng and Li, caused the fire by playing with matches", he said.

"Now Deng and Li are still in Beijing under supervision of their guardians and are subject to police investigation at any time," Liu said.

The South Korean girl was still in hospital, he added.

The children were among 51 students on a Mandarin language study tour in Beijing, one of many popular summer holiday courses drawing thousands of Hong Kong students to China each year.

On Monday, newspapers in the territory called for tighter controls on agencies organising the tours in Beijing.

A day earlier, a Hong Kong government spokesman called on people to join only tours organised by licensed companies.

(Xinhua News Agency July 18, 2002)