A child has died and another has been seriously injured after being stabbed and thrown from the window of an apartment block in Sweden.

The children, both under 10 years old, were found on the ground outside the building in western Stockholm on Sunday night.

One of them died overnight and another has life-threatening injuries, metro.co.uk reported.

Police suspect they were stabbed inside an apartment and then thrown 50ft down from a balcony.

A man and a woman have been arrested on suspicion of murder and attempted murder. They both had a relationship with the children, police said.

One of those detained was also apparently injured in the incident and is being treated in hospital before being questioned.

The children were taken to hospital by helicopter but one, the youngest, died during the night.

Police seized clothes from the apartment building and went door-to-door making inquiries, local media reported.

A cordon which was in place around the building had been lifted by Monday morning.