A gunman who attacked the Estonian Defense Ministry in the capital Tallinn Thursday has died, police say.

Earlier reports stated an armed man who had taken a hostage and fired shots in the ministry building had been arrested.

There were also reports of an explosion, Interfax news agency reported.

Hostages taken in the incident have been freed and no one else was injured, public radio said after workers were rapidly evacuated from the building which was cordoned off by police, and an investigation has begun.

According to initial reports, Estonian police received the first call about the shooting at 1510 EET, BNS reported, and bomb crews were dispatched to the scene.

Postimees, Estonia's largest newspaper, said personnel at the defence ministry had heard three shots.

A Defense Ministry official said a former soldier detonated an explosive device and fired off a shot before seizing a security guard, whom he later released, Estonian Public Broadcasting reported.

The building's foyer was reportedly full of thick smoke, and people were evacuated, the broadcasting outlet reported.

Defense Minister Mart Laar was not in the building at the time of the incident but arrived later.