The death toll in the fireworks accident at Sivakasi has gone up to 52. At least 50 were injured today in the devastating blaze that raged through a fireworks factory on the outskirts of Sivakasi, the country's cracker manufacturing hub.

The toll might go up as several persons were still feared trapped under the debris, police and fire brigade said, as the fire was doused by the evening amid intermittent explosions.

Officials said the dead bodies had been accounted for from hospitals at Sattur (16), Virudhunagar (13), Sivakasi (21). Two others died on way to a hospital in Madurai. Almost all those killed were workers, with some persons, who rushed inside the factory complex to try and rescue those trapped inside, also falling victim to the blaze, they said.

The tragedy struck when workers were engaged in mixing chemicals for fancy fireworks. The blaze gutted all 48 sheds located in the premises of Omshakthi fireworks factory, police and fire officials said.

They said the entire production had been stored in a godown against official advice. The sheds were reduced to ashes in the sprawling complex of the company and the debris had to be cleared to get a clear picture of the actual number of casualties, an official said.

Fire officials said that due to a variety of chemicals used in pyrotechnics crackers, there was thick and suffocating smoke, making their task difficult to enter the factory. The smoke could be seen 1.5 km away from the spot.

"These are times ahead of Deepavali. So activities go on at breakneck speed in the cracker units," Virudhunagar District Superintendent of Police Najmul Hoda said.

A factory official said 300 persons were at work at the unit at the time of the incident. Thousands of people thronged the area near the factory to inquire about the fate of their relatives working in the unit. In October 2009, 32 people, most of them Deepavali shoppers, were killed at a cracker godown fire in Pallipattu in Tiruvallur district.