Media playback is unsupported on your device Media caption Keith King, reporter for KSHB, said the explosion was "a huge fireball"

Search crews picking through rubble of a restaurant destroyed by a gas explosion in Kansas City, Missouri, have found the remains of one person.

Mayor Sly James declined to say whether the person was a man or a woman. An employee, a woman, was missing.

Six people injured in Wednesday evening's blast and inferno at JJ's eatery remain in hospital, three critically.

Officials suspect a utility contractor accident could be to blame.

At least eight others were treated and released after the explosion in the Country Club Plaza retail centre.

'Severe burns'

But Mayor James said at a news conference on Wednesday that officials could not be "100% sure that we can account for every single person that may have been at JJ's when the explosion occurred".

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Crews have been searching the site ahead of a major winter storm forecast to hit Kansas City later in the day.

"Search and rescue people are out there going through the rubble and will continue to go through the rubble,'' Mayor James said. "They will continue to investigate until weather shuts it down.''

Heavy equipment was brought in on Wednesday morning to clear several feet of debris.

Sniffer dogs were being used to search the smouldering wreckage for any human remains, city officials said.

After the blast, firefighters faced a massive blaze that appeared to have engulfed an entire block.

A doctor with St Luke's Hospital said two of the injured being treated there were in critical condition, one with "pretty severe burns".

Six others walked into the hospital with minor injuries.

Mr James said a total of 15 people had been injured. Six were still in hospital as of Wednesday morning.

Jill Chadwick, spokeswoman for the University of Kansas Hospital, told the BBC: "This patient told me there had been the smell of gas and that they had evacuated any patrons and that employees of the restaurant were in the process of shutting off gas valves and trying to get out of the restaurant when there was the explosion.

"He said the last thing he remembered was the roof collapsing. I asked him how he got out and he said the front of the restaurant was blown away and he just walked through the rubble."

Image caption One witness saw gas workers inside the restaurant before the blast

Kansas City Fire Chief Paul Berardi said firefighters were called about 17:15 local time (22:15 GMT) on Tuesday in response to a report of a breached gas line near the restaurant.

He said firefighters had left the scene after speaking to Missouri Gas Energy workers, about 45 minutes before the explosion occurred.

In a statement, Missouri Gas Energy said "early indications are that a contractor doing underground work struck a natural gas line".

The Missouri Public Service Commission, which oversees utilities, dispatched five employees to the site of the blast as part of an investigation.

Commission Chairman Kevin Gunn said preliminary information indicates that gas pipelines had been marked as required.

The initial blast was felt beyond the shopping area.

JJ's owner, Jimmy Frantze, told the Kansas City Star newspaper that he was driving back from Oklahoma on Tuesday night when he heard the news.

"It was 28 years of a great restaurant, and then it has to end like this," Mr Frantze said. "I want to check on my employees. I want to make sure they are all right."

The shopping area, established in 1922, is based on the architecture of Seville, Spain, and includes retail, restaurants, apartments and offices.