This is the heart-stopping moment workers made a quick retreat from a sinkhole when the walls started to crumble.

The men had been lowered into the abyss to connect ropes to vehicles that had been dragged into the cavity, which opened up during rush hour in Bangkok, Thailand, this morning.

But footage shows how tonnes of earth started to crash further into the chasm, with locals screaming as the engineers were winched back to safety.

Officials are now at the scene scratching their heads as they work out how to secure the sinkhole, which is believed to have been caused by a botched underground train construction that gave way at around 7am in the Dusit district of the Thai capital.

The 90ft wide sinkhole reportedly opened up in front of a hospital and police station on the bustling Samsen Road.

Terrifying footage captured onlookers screaming as concrete plunged 160ft into the abyss and electricity lines were dragged down in flashes of sparks.

Several police vehicles were also dragged into the hole, with one truck seen teetering on the edge.

Patients at the Vajira Hospital were evacuated amid fears that nearby buildings could be dragged into the chasm. Residents in the overlooking flats were also instructed to leave the area.

Miraculously, nobody is believed to have been injured. However, officials said 'two or three' police vehicles had been lost in the sinkhole.

Bangkok Governor Chadchart Sittipunt arrived at the scene at 8 am to assess the situation. He said recent construction from an underground train for the city's MRT purple line may have contributed to the collapse.

He said: 'Once the road was damaged, debris from the surface poured into the underground construction void, causing the area nearby to fall inside.

'A water pipe was damaged, causing a leak, which contributed to the issue. Nobody was injured, but damage to nearby buildings, including a new police station, is being assessed.'

Temporary Prime Minister of Thailand and cannabis campaigner Anutin Charnvirakul later arrived.

Police Lieutenant General Sayam Boonsom, commissioner of the Metropolitan Police Bureau, said the area was undergoing roadworks at the time of the collapse.

Officers said a damaged water pipe could have further caused the earth to weaken.

The police chief said: 'A preliminary assessment has found that construction activity may have caused the ground to sink and form a cavity underneath. The ground continued to subside.

'The area is being secured and investigations are ongoing into the cause, with several organisations working to assess the damage and the structural safety of the road.'