India, March 9 -- Norwegian police are investigating an explosion outside the US Embassy in Oslo early Sunday, officials said.

No injuries were reported. Police received reports of a "loud bang" or explosion around 1 am, Oslo police said in a news release.

The explosion was caused by some sort of incendiary device, Oslo police representative Frode Larsen said during a news conference Sunday. Investigators believe the embassy was the target and are searching for the perpetrators and their motive.

Local media reported minor damage to an entrance of the embassy, and people nearby said the street was blanketed in thick smoke following the blast. Police are seeking to talk to witnesses. PST, the Norwegian police security service, called in ...