Indian police are searching for the owner of a shop which they say had illegally stored explosives that triggered a blast, killing 90 people.

Most of those who died were at a neighbouring restaurant in Petlawad in the state of Madhya Pradesh.

Police earlier thought a faulty gas cylinder in the restaurant was to blame, but now say the blast was caused by illegally stored mining explosives.

The restaurant was packed with workers and schoolchildren eating breakfast.

Several dozen people were injured.

The shopkeeper, named as Rajendra Kasawa, had a licence for explosives for digging wells, construction and mining, district police official Seema Alava told AFP news agency.

But he had stored them "in an unauthorised way in a residential area" and was being sought on suspicion of culpable homicide.

State officials have ordered a judicial inquiry.

The restaurant was close to a busy bus stop. The blast knocked down a neighbouring building and damaged several others.

All the bodies were extracted from the debris, and black smoke from funeral pyres could be seen rising late into Saturday night.

Petlawad is in Jhabua district, where there are several manganese and bauxite mines.

Many mine workers are hired on contract from the town, which is about 850km (530 miles) south of the capital, New Delhi.