A Dutch policeman shot and killed his young children before turning the gun on himself, police have said.

The 34-year-old officer also seriously injured his 28-year-old wife, in a residential area, near the port of Rotterdam. The man's children were aged eight and 12.

Dordrecht Mayor Wouter Kolff said on social media there had been 'a very serious shooting incident' and that he was heading to the scene.

Photos from the scene showed a large police presence and at least one ambulance parked in a street as people stood in the street looking on.

Forensic technicians are seen following a shooting in Dordrecht, Netherlands in which three people died

Dordrecht Mayor Wouter Kolff said on Twitter there had been 'a very serious shooting incident' and that he was heading to the scene (pictured)

A shooting has been reported in the Dutch city of Dordrecht, which is located near Rotterdam

Police secure the area after a shooting in the Dutch city of Dordrecht

Rotterdam police tweeted that 'three people have been killed and another was seriously wounded' but did not give any further details.

'We are at the scene with numerous people to investigate the cause of the incident,' police said, adding that more details would be given later.

Police said emergency response teams were at the scene to treat victims and investigate the shooting.

Dutch broadcaster NOS said the shooting was at a home and that emergency services were at the scene.

No additional details of the incident were immediately available.

The condition of the fourth victim is not known.

Dordrecht lies around 25 kilometres (15 miles) southwest of the port city of Rotterdam and is one of the oldest cities in the Dutch province of South Holland.