Both blasts hit central Stockholm as the streets were busy with people out Christmas shopping.   

The car exploded at 17:00 (16:00 GMT) on December 11 and the second blast occurred 10-15 minutes later on a street about 300m away, police spokesman Kjell Lindgren said. 

A man was found dead near the site of the second explosion and two people with minor injuries were also found nearby. 

Swedish press attributed the second blast to a suicide bomber but police said no cause had yet been determined.

Foreign Minister Carl Bildt said a "terrorist attack" which could have been "truly catastrophic" had failed. 

A local news agency, TT, said it had received a threatening e-mail shortly before the blasts, which called for "mujahideen", or Islamist fighters, to rise up in Sweden and Europe. 

Attacking the country over caricatures of the Prophet Mohammed drawn by Swedish artist Lars Vilks as well as Sweden's military presence in Afghanistan, the e-mail promised Swedes would "die like our brothers and sisters". 

Sweden has 500 soldiers deployed in Afghanistan as part of the international peacekeeping force.