Six people, including four tourists, went missing after an explosion caused a two-storey building to collapse in Athens’ historic Plaka district on Friday morning. Authorities suspect a major gas leak caused the blast. The explosion happened around 7:30 am local time on a small street below the Acropolis.

Athens Mayor Haris Doukas called the incident an "unbelievable disaster". He said a "explosion triggered by... a very significant gas leak" may have caused the building to collapse. Police increased the number of missing people from five to six on Friday evening.

Rescue teams search for survivors

Rescue teams continued their search through the night. Firefighters used heavy machinery to clear the rubble. "Operations are continuing, all the machinery is here, the search will go on throughout the night," Doukas said after visiting the site.

"These are difficult hours. We stop whenever necessary to keep silent, so we can see if we can hear any sound" made by possible survivors, he added.

Greek public broadcaster ERT reported that a British citizen and a Greek woman lived on the second floor. Four American tourists stayed in short-term rental accommodation on the first floor. The explosion shook the area and caused damage to nearby buildings and vehicles.

Firefighters use search dogs and thermal cameras

Around 30 firefighters reached the site with six vehicles and three search and rescue dogs, Greek news agency ANA reported. Rescue workers used excavators to remove the debris. They also used thermal cameras to look for people trapped under the rubble.

"The damage extends along the entire street as well as the street behind the building," Doukas said. Earlier, rescuers pulled two women from a nearby building. They took both women to hospital. Another person suffered minor injuries from falling debris.

Nearby buildings face safety checks

Doukas said two neighbouring buildings were also in poor condition. "We are talking about an incredible disaster," he said. Authorities have started safety inspections on the adjoining buildings. Officials will decide whether the structures can remain standing or need demolition.

Mathaios Artavanis, the owner of the ground-floor apartment, told Kathimerini that he tried to contact the elderly residents. He said he could not reach "the elderly couple, around 70 years old".

Explosion hits busy tourist district

Plaka ranks among Athens’ most popular tourist areas. The neighbourhood sits close to the Acropolis and Hadrian's Arch, a major Roman-era monument. The explosion occurred during the busy tourist season. Hundreds of foreign visitors normally fill the narrow streets in the area.

Rescue teams continued searching the collapsed building as authorities investigated the suspected gas leak and assessed the safety of nearby structures.