One person has been killed and at least one other hurt as two explosions rocked the centre of the Swedish capital, Stockholm, police say.

A car blew up near the busy shopping street of Drottninggatan, and another explosion hit nearby minutes later, AP news agency quoted police as saying.

A man's body was discovered after the second blast, the agency reported.

Swedish Aftonbladet newspaper showed images of a burning white car. The cause of the blasts is not yet known.

Rescue services spokesman Roger Sverndal said the car which exploded had contained gas canisters, AP reported.

A former AP worker, Gabriel Gabiro, was close to the second blast.

"I saw some people crying, perhaps from the shock," he told the agency.

"There was a man lying on the ground with blood coming out in the area of his belly, and with his personal belongings scattered around him."

Aftonbladet said police had cordoned off the area and emergency services were at the scene.