LONDON

A heavy explosion shook an apartment building in Solna, north of Stockholm late Thursday evening.

The blast happened at 22:45 Central European Time (0122GMT).

"We believe that it is an explosion that someone has caused," Jari Kalliorinne, a police officer in charge of the police in the StJari Kalliorinneockholm region, said on Friday morning.

No arrests were made and nobody was injured at the scene.

It remains unknown if the explosion was targeting a specific apartment or it is related to gang violence.

"It's too early to speak on it," Daniel Wikdah, police press spokesperson, told newswire TT.

The explosion was felt as far as central Stockholm, according to testimonies given to newspaper Expressen earlier.

"It felt like an earthquake," Yngve Sjoman, who lives in the property opposite told Expressen.

The explosion damaged the ground floor and entrance and shattered the windows.

"I'd just gone to bed. I've never been through anything like it. I still have a pulse. It was a hell of a fall," said a woman who lives at the building.

Yngve Sjoman, who lives just across the building, was watching TV with his wife when he heard the explosion.

"It felt like an earthquake. It was such an incredible bang," he told Expressen.

"I knew what it was when I looked out the window and saw how there were a lot of cops, fire trucks and ambulances just outside," he said.

Another resident said that the whole house "was shaking and all the neighbors came out and stood on the balconies."

Residents are being evacuated and are still unable to return to their apartments as rescue teams are still present at the scene.

Another two explosions happened previous evening when an apartment building in Astorp, Skane and later an apartment building in central Helsingborg exploded.

A man in his 20s has been taken to hospital with serious injuries, however it is not known if he was the target of the attack.

Police in Skane said that both explosions were powerful but it is too soon to say whether the two incidents are in any way connected to other recent bombings in the area.