A massive explosion Friday on a state-owned gas pipeline running through the southern Indian state of Andhra Pradesh killed at least 16 people and gutted scores of homes, a state minister said.

"At least 16 people are dead. We have recovered 13 bodies so far," state home minister N. Chinna Rajappa told AFP after the blast near a refinery in the East Godavari district.

Television pictures showed flames at least 10 metres (30 feet) high leaping into the dawn sky, scorching trees in a surrounding coconut grove in the coastal area where many live in flimsy huts.

The fire on the 18-inch (45-centimetre) pipeline owned by the Gas Authority of India Limited (GAIL) was extinguished by mid-morning and the gas had been cut off, a senior administrative officer told AFP by telephone from the scene.

At least 15 people were hospitalised with injuries from the explosion, which occurred around 06:30 am (0100 GMT), the company said, while the cause of the blast was not yet known.

"We are currently focused on rescue and relief operations," GAIL chairman B.C. Tripathi was quoted as saying by the Press Trust of India (PTI) news agency.

GAIL is the country's largest state-owned natural gas processing and distribution company and its website shows it has a pipeline that transports liquefied natural gas in the area of the explosion.

Witnesses contacted by phone told AFP that angry locals had entered an office belonging to GAIL near the site of the accident, pelting it with stones and vandalising property.

Prime Minister Narendra Modi said he had asked the petroleum minister and other senior officers to ensure immediate relief at the accident site.

"My thoughts with the families of those who lost their lives in the GAIL pipeline fire. Prayers with the injured," he tweeted.

Petroleum Minister Dharmendra Pradhan told reporters that an investigation had begun.

"Our first priority is to take care of the rescue, relief and restoration efforts there and to see that the fire does not flare up further," he said.

The state government has ordered an enquiry and will set an action plan to avoid similar accidents in future, Chief Minister N. Chandrababu Naidu said.

Earlier this month six people were killed by a poisonous gas leak at one of India's largest government-owned steel plants in central Chhattisgarh state.

India's biggest offshore gas fields are located in the Bay of Bengal to the east of Andhra Pradesh.