Car bomb strikes Madrid

A car bomb has exploded in Madrid, on the outskirts of the city centre.

Police said it was not immediately known if there were any injuries.

Witnesses told the Reuters news agency they had heard a powerful blast.

The explosion occurred just after 0900 (0800 GMT) on Corazon de Maria street, on the northeastern edge of the city centre.

Cadena SER radio described it as a residential area.

The Basque separatist group ETA has frequently carried out car-bomb attacks in its campaign for independence.

It has killed some 800 people over the last 33 years.