ZHENGZHOU, March 3 -- Twenty members of a Chinese opera troupe were killed and 13 others injured when their bus fell off a cliff in central China's Henan Province late on Monday night as they were on their way to stage a performance.

The crash occurred at around 11 p.m. near the boundary between Xinxiang City and Linzhou City when the bus with 33 people aboard was heading for Linzhou, said the local rescue headquarters on Tuesday.

Those killed and injured were all members of a privately-owned opera troupe from Xingyang. Their rented vehicle left Jiayu Township in Xingyang at 7:30 p.m. on Monday for Linzhou.

The injured are being treated in several hospitals. Three remain in intensive care units and are in stable condition, according to the city government of Anyang, which has jurisdiction over Linzhou.

The other injured passengers suffered bone fractures or bruises with no danger to their lives.

The troupe was unregistered and had no performance license, said local culture administrators. The troupe's chiefs as well as the owner and driver of the bus have been detained by police.

"It was a sharp left-hand bend on a downhill stretch of road. The bus was going way too fast and its brakes couldn't stop it. It turned over on one side and then plummeted off the cliff edge," said Mao Yike, one of the troupe members on board.

Mao said he was thrown out of a bus window as it was falling. He slightly injured his forehead and left hand and is being treated in the Linzhou Traditional Chinese Medicine Hospital. Mao said he managed to rescue a teenager and the wife of the troupe's head in the darkness.

"The driver in his 50s or 60s was going very fast. We felt very nervous and advised him to slow down several times, but he ignored our suggestion, sort of taking advantage of his seniority," said Mao, 24.

Some passengers were asleep when the accident happened, according to Mao. He was playing with his mobile phone.

"I was seated in the back row. When it fell, I was crushed by others and then thrown out of the bus," said 13-year-old Liu Yuan, whose right leg was fractured.

Three injured people, aged 60, 43 and 35, were admitted to the Linzhou Traditional Chinese Medicine Hospital at around 4 a.m. on Tuesday, said Qin Fuqiang, the hospital's vice president. The three have been transferred to two hospitals in Anyang for treatment.

Qin said his hospital later received three more injured passengers, including a 15-year-old.

More than 300 people joined the rescue work, which ended at 5 p.m. on Tuesday.

The cause of the accident is under investigation.