A group of people broke into Libya's embassy in Stockholm Thursday and at least one appeared to be threatening to jump from a window, police said, adding the break-in seemed to be part of a demonstration.

"A number of men have broken into the embassy, but there was no embassy personnel there," police spokesman Lennart Loefgren told AFP, adding it remained unclear how many people were inside the mission.

"At least one person is hanging out through a window," he said, adding the person appeared to be threatening to jump and that rescue services were setting up an inflatable mattress below the window.

"I don't know how high up it is," he said.

"It appears to be some kind of demonstration.... There are four to five people outside with some kind of flag," Loefgren said, unable to provide details on the type of flag.

One guard was outside the embassy at the time of the break-in, but it appears that the demonstrators themselves tripped an alarm, alerting police to the intrusion at 10:45 am (0845 GMT), he said.

Around 15 police patrols had arrived at the scene and blocked off the embassy building and the surrounding area.

Sweden in May expelled two Libyan diplomats accused of inappropriate activities, reportedly Tripoli's last two representatives in the Scandinavian country.

Swedish Foreign Minister Carl Bildt said in early March, before the NATO-led air strikes against Moamer Kadhafi's regime began, that he no longer considered the Libyan embassy in Stockholm a legitimate representative of the Libyan people.