At least 18 people were killed in southern Russia when a bus carrying construction workers plunged into the Black Sea on Friday, Russian investigators said.

Eight more people were injured, five of whom were in a serious condition, Interfax news agency reported, citing the
emergency ministry which carried out rescue works.

There were around 40 people on the bus, which fell from a several-meter-high pier, a part of oil shipment infrastructure on the Black Sea coast.

Investigators didn’t immediately say why the bus drove off the pier on Friday morning, but the crash was likely caused by a failure in the vehicle’s braking system, said Oteko Portservice company, which runs the shipment facility.

A picture from the scene, published by the emergency ministry on its website, showed a group of divers on two boats
searching waters underneath the pier.

Government investigators were looking into possible violation of security rules and traffic regulations.