SHANGHAI, Jul 6 -- POLICE in northeast China were interrogating waitresses and the owner's wife yesterday after an explosion in a karaoke parlor killed at least 25 people and injured 33.

Four of those hurt in the Wednesday night blast were in a serious condition last night.

The wife of the owner of the privately run music bar in Benxi, Liaoning Province, and the bar's employees have been detained, Xinhua news agency reported yesterday.

Rescuers found 25 bodies in the debris including the parlor owner, surnamed Qu, said an official in charge of the emergency response.

Police said yesterday they had finished clearing debris at the scene and submitted evidence to determine the cause of the blast.

The two-story building, which also held a bathhouse, was destroyed in the explosion. Several vehicles were buried underneath the debris.

The blast also caused a blackout in the area as the electricity network was also damaged. Windows were also shattered in nearby buildings.

"I was watching my grandson finishing his lessons. Suddenly, we heard a big bang, then the door burst open from effects of a powerful shock wave and the lights went out," said Chen Xiaohong, a 77-year-old resident who lives 50 meters from the karaoke parlor.

"We were lucky not to have been hurt," he said.

Meng Xianling, owner of a seafood stall across a narrow lane from the building, and her 13-year-old son were awakened by the explosion to see shattered windows and shingles blown off the roof.

"I was afraid the parlor's boiler would explode. Mercifully, it didn't," she said.

The explosion was the latest in a string of blasts, fires and accidents in shopping malls, cinemas and other public places across China despite repeated government efforts to improve safety. Many of the mishaps were blamed on lax safety procedures and negligence.

In 2005, a fire in an illegally run bar in the southern city of Zhongshan killed 26 people. Officials said the bar lacked fire extinguishers and its emergency exit was too narrow.

In China's worst nightclub disaster, a fire blamed on a welding accident swept through a disco in the central city of Luoyang in December 2000, killing 309 people.

Reports at the time said the building had failed 18 safety checks in two years.

Investigators blamed locked emergency exits for the heavy casualties. They said the exits were closed to prevent people from sneaking in without paying.

With emergency stairwells shut off, the only way out of the disco was a single elevator. Many of the bodies were discovered crowded around the locked stairwells.

A court sentenced 23 people to prison terms of up to 13 years over the incident.

Last December, China executed two men found guilty of causing explosions at two Internet cafes in central China that killed two people. The men were punished in connection with blasts in May 2006 at two cafes in Hefei, capital of Anhui Province.