BEIJING -- A fire possibly caused by a short circuit engulfed a theater in northwestern China, killing more than 300 children and teachers who were watching a variety show.


The panicked audience bolted for the exits Thursday night as flames and smoke filled the Friendship Theater in Kalamayi, 2,600 kilometers northwest of Beijing, the official Xinhua News Agency said.


Most of the 300 killed were primary school students from the city, Xinhua said. More than 100 were injured, and officials suggested the casualty toll would rise in this latest of a series of deadly blazes in China.


An official in the foreign affairs office in Kalamayi, who gave his name only as Mr. Sun, said the number of deaths and serious injuries was changing, indicating the death toll was likely to rise. He refused to give an estimate.


An initial investigation showed the fire may have been caused by a short circuit, Xinhua said.


Rescuers worked through the night to try to save lives, the report said.


Officials contacted by phone in Kalamayi refused to give details, and one woman said local leaders had imposed a news blackout. But an official told Cable News Network that 754 people were in the cinema, and that 310 were killed and 150 injured.


The British Broadcasting Corporation reported that most of the children who were killed had been crushed in the stampede to leave the building, and others succumbed to smoke and fumes. It said the fire began after an explosion in electrical wiring. The report did not cite any sources.


An official of the local fire department, who would not identify himself, denied reports that some doors of the theater had been locked, blocking escape. The official would not give any details.


The State Council, China's Cabinet, issued an emergency circular in response to the fire. It said businesses that fail to meet fire safety standards will be shut down, and ordered immediate fire-prevention inspections nationwide. It also called on officials to check new projects more carefully for fire-safety measures before approving them.


China has been plagued by a series of serious fires recently.


Last week, a fire in a dance hall in northeastern Liaoning province killed 233 people and injured 16. The recently renovated building had only a single narrow exit, and most of the victims died of smoke inhalation.


Three days later, 11 people were killed and 38 injured in a hotel fire in coastal Shandong province. It took nearly 100 firefighters an hour to bring the blaze under control.