Police declared the sinkhole in Lewisham a ‘major incident’. Photograph: Jonathan Haynes

Firefighters rescued passengers in south London after a sinkhole caused by major flooding swallowed part of a coach.

Onlookers said the road looked like a river after the hole opened on Lewisham’s Lee High Road on Saturday, following a burst water main. Footage on social media showed the emergency services dealing with the vehicle, which was stuck in several inches of water.

Police declared a major incident, cordoned off roads and asked residents to avoid Lewisham town centre. Homes in the surrounding area were left without water and a temporary shelter was set up on Bonfield Road for those displaced due to flooding.

Thames Water said repairs were “complicated and taking longer than normal”.

Transport for London said the road closures meant 18 bus routes were on diversion on Sunday but that there were no excessive delays.

Sinkholes occur when water gradually dissolves soluble bedrock, forming a cavity under the ground over thousands of years. Loose sedimentary rock closer to the surface gradually falls into the hole, until the surface is no longer able to support itself and collapses.

South London was hit by a similar incident earlier this year when a 13ft sinkhole opened above a sewer in Forest Hill, causing major disruption to commuters due to damage to rail tracks.

More sinkholes have been appearing around the UK in recent years. In 2014, scientists recorded a five-fold increase in the number of sinkholes occurring over a particularly rainy winter.

Although sinkholes are closely linked to rainfall, humans can exacerbate the process. Anything that has the potential to divert water to weak points beneath the earth will accelerate the creation of sinkholes.

Earlier this month, a 20-metre sinkhole opened up in the centre of the Japanese city Fukuoka. People were forced to evacuate nearby buildings as the sinkhole filled with water, but there were no injuries and the hole was filled in a two days by authorities.

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