A British family of four are among at least six missing people after a huge explosion which destroyed a building in Athens after a suspected gas leak. 

According to local reports, a British man, his wife, their son and their son's partner were staying in what is believed to be an Airbnb apartment. 

However it is not known whether the family of tourists were inside at the time of the explosion.  

Meanwhile an elderly couple who lived on the second floor of the property are also missing.  

It comes after a massive explosion tore through a building in a historic district of Athens before the structure collapsed. 

The explosion happened at around 7.30am today in the district of Plaka, which sits just round the corner from the Acropolis of Athens and the Temple of Zeus. 

Officials said earlier that five people are missing and local media has reported three Americans were among those who have not been located, but this has not yet been confirmed. 

Several people were injured by the blast, on Lysikratous Street, with local media reporting that two women from an adjacent building were taken to Georgios Gennimatas Hospital.

Meanwhile a passerby said they suffered shrapnel wounds from the explosion. 

The fire service said they were looking for two elderly people who lived on the building's top floor, and three tourists who are believed to have rented the apartment below.

The ground floor is believed to be uninhabited while the first floor flat where the British family were staying is understood to be an Airbnb and the second floor was the home of the missing elderly couple.  

A fire service spokesman said: 'A search and rescue operation with a dog is underway to find anyone who may be trapped.

'We have learned that an elderly couple and three other people staying in a holiday rental were living in the building, and we are trying to determine whether they were there at the time of the explosion.'

Fire crews remain at the scene and are searching through debris for the missing people, it has been reported. 

Thermal cameras and a trained dog have been deployed to aid rescue efforts. 

Drones have also reportedly been deployed to help locate those missing. 

The mayor of Athens, Haris Doukas, told Protothema: 'There are missing persons, it is a very complex situation, the investigation is in full swing.'

When asked if there were people trapped beneath the rubble, Mr Doukas said 'there is great fear, there are competent senior Fire Department officials who will answer you'.

He added: 'There are missing persons and it is a very complex situation, that is why dogs are inside at the moment and are investigating.'

Mr Doukas said: 'The explosion was of great force, the destruction was extreme.'

The explosion, attributed at this stage to a gas leak, destroyed the two-floor building and also damaged neighbouring homes.

When asked about whether the explosion was caused by a gas leak, Mr Doukas told reporters: 'I understand that it was caused by gas and its intensity was terrifying.'

He added that there has been a 'very large degree of damage'.  

The explosion broke windows in surrounding buildings and damaged cars parked nearby.

After several hours on Friday, no sign of the missing persons had been found in the debris.

Two women in a neighbouring building were hospitalised with minor injuries, state TV ERT said.

A third person who was passing by was also lightly injured, the station said.

The owner of the building's ground floor first found out about the incident via the news.

Matthew Artavanis said he could see it was his building from the photos he saw of the explosion. 

He immediately called his neighbour at around 8am for more information – but the elderly couple didn't answer. 

'There's no sign of them, from the photos I saw,' Mr Artavanis said.

He added that the husband of the couple had mobility issues.