In Oslo, Norway an explosion at a government building shattered windows and sparked momentary chaos. The blast happened at government headquarters in the Norwegian capital around noon on Friday, injuring several people.

The 17-story building holds the Prime Minister's office, and is near to Norway's biggest tabloid newspaper VG, according to The Telegraph.

I see that some windows of the VG building and the government headquarters have been broken, one witness told public radio NRK.

The first injury count comes from a Reuters correspondent, who said he counted eight injures so far. Some reports say the figure is in the dozens.

Fire and smoke from the explosion can been seen in many parts of the city, reports say.

The cause of the blast is currently unclear, and police and fire officials have not made any comments. It is not known if the blast was a terrorist attack. No casualties have been reported.

The building was evacuated immediately, and no other buildings in the city have been told to clear out.