At least 13 people have been killed in an explosion at a firecracker factory in India's southern state of Kerala, officials say. The incident took place in Thrissur, where around 40 people were believed to be assembling firecrackers in a cluster of sheds for an upcoming festival. Several others were injured, with five reported to be in critical condition.

This was the second such incident this week. On Sunday, a blast at a firecracker factory in neighbouring Tamil Nadu state left at least 25 dead.

Accidental explosions are a grim routine in India's fireworks industry, recurring with troubling regularity - most visibly around Sivakasi in Tamil Nadu, which produces much of the country's supply.

The explosion occurred on Tuesday around 15:30 local time (10:00 GMT), triggering secondary blasts that complicated rescue efforts. Workers were making firecrackers in temporary sheds near paddy fields with poor road access, hampering emergency response.

The force of the blast was felt kilometers away, leading some residents to initially think it was an earthquake. Eyewitnesses described chaotic scenes as locals joined rescue efforts, pulling out the injured and dead.

Kerala's Revenue Minister K Rajan stated that all fireworks units preparing for the upcoming Thrissur Pooram - a major annual Hindu temple festival - had obtained permission to manufacture and store fireworks in designated areas.

The festival, famous for its grand fireworks displays, involves Thiruvambady and Paramekkavu Bhagavathy Temples, with the main event scheduled to draw large crowds.

Officials reported that food had been prepared for approximately 40 workers, indicating that at least that many were present when the explosion hit.

While officials are investigating the cause, local leaders suggest that high afternoon temperatures may have played a role. A magisterial inquiry has been ordered to determine the circumstances of the incident.

Kerala Chief Minister Pinarayi Vijayan has pledged to bring in medical experts from other states to treat the burn victims as necessary. Prime Minister Narendra Modi announced financial assistance of ₹200,000 (around $2,137) for the families of the deceased and ₹50,000 for those injured.

Firecracker factory accidents are common in India due to the handling of highly volatile chemicals in cramped and low-cost facilities. The industry, largely informal, supplies fireworks for various occasions and is often scrutinized for inadequate safety standards.}