"Bodies of 13 people charred in the incident were recovered from the gutted houses. Two others succumbed to their burn injuries while undergoing treatment at different hospitals," Amalapuram DSP M Veera Reddy said.
18 injured people were shifted to different hospitals in the district, another police officer said, adding the deceased include five women, three girls and a boy.
The leaping flames from the state-run Gas Authority of India Limited (GAIL) pipeline at Nagram village in Mamidikuduru Mandal of the district quickly swept through nearby houses and coconut plantations, leaving behind a trail of destruction.
"The blast and subsequent blaze which started around 5 AM spread swiftly engulfing houses, coconut farms and vehicles parked in the vicinity. In 15 minutes everything was gutted," the police officer said.
The fire got apparently triggered when a tea shop vendor lit up a stove, setting off a blast, IGP North Coastal Zone Atul Singh said.
A GAIL official, however, quoted its Chairman B C Tripathi as saying, "The exact cause of the blast is not immediately known. After an inquiry only we will get the details and cause of the blast."
An 18-inch pipeline feeds gas to Lanco's Kondapalli power plant near Vijaywada.
Petroleum Minister Dharmendra Pradhan has ordered a high-level inquiry headed by a Joint Secretary in his ministry. The probe panel will have officials of Oil Industry Safety Directorate, NDMA and Hindustan Petroleum Corp Ltd (HPCL) as members but GAIL and ONGC, from whose fields gas was being supplied, have been kept out of it.
The blaze occurred barely a few hundred metres from ONGC's Tatipaka Refinery located at the village.
"The gas pipeline has been shut. Fire has been controlled. This is a very serious situation and I have ordered a high-level inquiry into the incident," Pradhan, who is scheduled to visit the scene, told reporters in Delhi.
Petroleum Secretary Saurabh Chandra, GAIL Chairman B C Tripathi and ONGC Chairman D K Sarraf are scheduled to accompany him.
President Pranab Mukherjee, Prime Minister Narendra Modi and Congress chief Sonia Gandhi have condoled the loss of lives in the tragedy.
Modi has announced an ex-gratia relief of Rs two lakh from the PM's Relief Fund for the next of the kin of those killed.
"My thoughts (are) with the families of those who lost their lives in the GAIL pipeline fire in AP. (My) prayers (are) with the injured," Modi said.
Andhra Pradesh Chief Minister N Chandrababu Naidu has also ordered an inquiry into the incident. Naidu, who is in Delhi, is rushing to the spot after cuttting short his trip.
Naidu spoke to Deputy Chief Minister N Chinarajappa and East Godavari district Collector Neetu Prasad over phone and directed them to provide best medical facilities to the injured.
Chinarajappa, who has reached the spot, said a comprehensive inquiry will be conducted into the incident.
"The state government will conduct a comprehensive inquiry. All help will be provided to the blast-affected persons," said Chinarajappa, who is also the state Home Minister.
Meanwhile, angry villagers tried to attack the local office of GAIL with stones but timely action by the police thwarted their attempts.
Some villagers alleged foul smell of gas was being felt by many since last night but officials took no action.
They complained about lax attention towards safety despite the pipeline running through residential areas of the village.
"The local residents are angry because they feel that the GAIL authorities did not bother though smell was coming from the rusting pipeline. Home Minister (N Chinarajappa) and district officials are talking to them," Finance Minister Y Ramakrishnudu said.
When asked about villagers' claim about foul smell of gas emanating from the pipeline since last night, a police officer said it needed to be verified. "A detailed probe is on," he said.