LONDON • Three people were killed and six injured Wednesday when a passenger train derailed in northeast Scotland after heavy rain and flooding hit the area.

The train driver was believed to be among the dead, British Transport Police said. The Rail, Maritime and Transport union said that the train conductor was also believed killed. Formal identification has yet to take place. Six people were hospitalized, but their injuries are not considered serious.

Images from the scene show that several cars of the four-carriage train had left the tracks and one had tumbled down an embankment. Smoke was seen billowing from the wreck. Air ambulances and coast guard helicopters came and went as the rescue operation unfolded.

Prime Minister Boris Johnson said a police investigation aims to find out what caused the derailment and ensure “nothing like this happens again.”

“As I understand there was about a month’s worth of rainfall in a very short period which undoubtedly aggravated the problem there,” he added.

Torrential rain had caused flooding and travel disruptions in Scotland, and on Wednesday morning Network Rail Scotland tweeted warnings of a landslip affecting services in the area.

It was not clear how many people were on the train, an early morning ScotRail service from Aberdeen to Glasgow.

British Transport Police chief superintendent Eddie Wylie said the derailed train was not a busy service, “and from (closed circuit television) inquiries and witness statements we believe all passengers have been accounted for.”

“However, once the area has been made safe, then a full and thorough search will be conducted, which is likely to take some time,” he said.

Scottish First Minister Nicola Sturgeon described the derailment as a “major incident and said she would be convening an emergency response meeting.

The transport police said officers were called at 9:43 a.m. to the railway line near the coastal town of Stonehaven, about 100 miles northeast of Edinburgh and south of Aberdeen.

Local lawmaker Andrew Bowie had been in Stonehaven surveying flood damage earlier Wednesday.

“The situation was really bad this morning. The River Carron, the main river which flows through it, had burst its banks, and the heavy rain had caused flooding in the center of Stonehaven and lots of the side streets leading off it,” he said.

Emergency services attend to the scene of a derailed train Wednesday in Stonehaven, Scotland.

the associated press