CHENNAI: Indian police arrested 12 people on Thursday and were hunting for the boss of a fireworks factory where 38 people were killed in a blaze that highlighted the industry’s lax safety standards.

Firefighters battled for hours to control the fire that broke out on Wednesday afternoon at the Om Sivasakthi plant in Sivakasi, the centre of the Indian fireworks industry, 700 kilometres from the southern port of Chennai.

“We have managed to arrest 12 employers who were responsible for the safety of the workers. They have all been charged with culpable homicide,” senior police officer Najmul Hoda told AFP.

Hoda listed a string of violations in the plant, adding that its production licence had been revoked but operations had continued regardless.

“Not more than 160 people are allowed to work, but there were around 400 persons inside the premises,” he told reporters at the scene.

The fire safety system had not functioned when an initial fire broke out – reportedly because of a mistake in mixing chemicals – and the premises had been sub-let to a third party, which is illegal.

“The original owner cannot leave the factory to someone else,” Hoda said, adding that police were trying to track down the owner for questioning.

“As the investigation progresses, all those persons against whom complicity is established would be arrested,” said Hoda.

The fire started in a small room that was packed with workers and swiftly spread to dozens of other rooms where explosive chemicals and finished fireworks were being stored, fire and police officials said.

Noxious smoke could be seen billowing from the premises, with exploding fireworks and chemical fires posing a danger to firefighters and local people who gathered to watch the inferno on Wednesday.

Badly burnt or injured people were evacuated by onlookers or fellow workers, with some travelling in ambulances to three local hospitals and medical centres. Seventy are being treated for injuries, some with severe burns, Hoda said.

Prime Minister Manmohan Singh on Thursday expressed his condolences to relatives of the dead and to those injured.

Sivakasi, which is home to some 700 fireworks factories, is running at peak production ahead of the forthcoming festival season, which includes Diwali, the festival of lights, when Indians celebrate by letting off firecrackers.

An estimated 40,000 workers are employed in the fireworks industry in the small industrial town, often assembling products with little or no safety gear while sitting on bare floors.

The latest tragedy in Sivakasi comes after at least 20 people were killed in another blaze at a fireworks factory in the town in July 2005.

Safety measures in Indian factories are routinely ignored because of a lack of inspections or corruption.

The United Nations’ International Labour Organisation (ILO) estimates that nearly 50,000 Indians die from work-related accidents or illness each year.