Footage on Indian television showed a tower of flame after the explosion at the firecracker plant, with dozens of ambulances sent and army helicopters called in to evacuate the wounded.

Senior district police official Rajeshwari Mahobia told AFP there were "eight deaths so far and around 80 injured", at the factory in Harda in Madhya Pradesh state, adding that "the death toll is likely to go up".

Madhya Pradesh Chief Minister Mohan Yadav said reports of the explosion were "very sad news" and said medics at burn units in nearby major hospitals had been asked to "make necessary preparations".

"Ambulances are being rushed to Harda from the surrounding areas, and the army has been contacted to arrange for helicopters," Yadav said in a post on X, formerly Twitter.

At least 20 ambulances were at the site, with 50 more being sent to help those injured, he added.

Dr Manish Sharma, a surgeon at the Harda district hospital, said the centre had been flooded with a stream of casualties.

"We have eight deaths at our hospital, a total of 90 people were admitted here so far and we have referred 15 of them to a bigger hospital," Sharma told.

"As more people are being rescued from the site, they are being brought here."

Kailash Chand Parte, a senior district official who is coordinating rescue efforts from the factory, said fire engines were battling the fierce blaze.