One person has been killed and eight others injured in an explosion at an apartment building in northern Spain.

The Navarra regional government said police are investigating the explosion in the town of Puente la Reina, near the city of Pamplona, at 1.30am local time on Sunday.

The body was found in a first-floor apartment but it is yet to be identified. Police believe it could be the tenant, an 80-year-old man.

The three-storey building in Spain  was evacuated due to damage to its structure
The three-storey building in Spain was evacuated due to damage to its structure (Alvaro Barrientos/AP)

Flying glass and bricks from the explosion hit eight passers-by in the street, and four people were taken to the hospital. One of them is in a serious condition.

The three-storey building was evacuated due to damage to its structure.