An investigation has begun after two psychiatric patients escaped from a secure clinic at the weekend, one of whom was shot dead by police.

The two men forced a staff member to let them out of the Kijvelanden clinic in Poortugaal, near Rotterdam, on Sunday afternoon and flagged down a taxi. Police gave chase along the A15 motorway and stopped the car near Kesteren, where they opened fire as the men tried to flee across an industrial site.

The staff member was taken hostage at knifepoint by one of the patients, who ordered him to unlock his accomplice’s room and then let them leave by the front door. A spokesman for the clinic said the staff member had received a slight knife wound to his neck.

‘He is badly shocked. It’s a big shock for the other people in the clinic too,’ said the spokesman.

The surviving patient and the taxi driver were arrested and are currently in custody. The independent investigation department Rijksrecherche has begun an inquiry, as is standard practice when police fire their guns on duty.

The inquiry will also focus on how the patients managed to get hold of a knife in the clinic. They had been kept apart because they were both assessed as high escape risk.