Dutch investigators are focusing on maintenance work as a possible cause of a deadly rail accident near The Hague. According to rail network company Pro Rail, the passenger train struck a small crane on the track, causing three carriages to derail.

One person has died and some 30 passengers have been injured, many of them seriously.

The accident happened around 3:25 am on Tuesday in the town of Voorschoten, near The Hague, sending one carriage into a field next to the tracks.

John Voppen, CEO of Pro Rail, called the accident "a black day for Dutch railways".

 Television images showed rescue workers using makeshift bridges to cross a canal running alongside the rails to reach the stricken train in the darkness.

Many windows in the train carriages were broken. It was not clear if that happened during the accident or as passengers attempted to escape.

Injured passengers were treated in nearby homes and transported in a fleet of ambulances to hospitals, including a “calamity hospital” opened in the central city of Utrecht.

“This is an incredibly tragic accident. I sympathise with the victims. Unfortunately, there is also a fatality to mourn. My thoughts go out to all the family and friends of those involved,” Voorschoten Mayor Nadine Stemerdink said in a statement.

Dutch King Willem-Alexander visited the site of the train collision on Tuesday afternoon, where he also extended his condolences to the victims' families.

Rail travel accidents in the Netherlands are relatively rare and the country has a good record on rail travel safety.