Stockholm police stormed the Libyan embassy Thursday and arrested seven people who had broken in and appeared likely to try to kill themselves or set fire to the building, police said.

"We tried to negotiate with these people, but came to realise that the negotiations would not succeed, and since there was a real danger that human lives could be lost and of serious material damage, we went in," police spokesman Ulf Goeranzon told AFP.

"We arrested seven people. They have been removed from the building and they are now being interrogated at a police station," he said, adding that all of those arrested were men, and that it remained unclear if more people had participated in the break-in.

The group had broken into the Libyan embassy in Stockholm Thursday morning in what appeared to be a protest action, and police had been alerted to the intrusion at 10:45 (0845 GMT) when an alarm inside the building went off.

"They hung out a banner on the facade of the embassy indicating that they would kill themselves if we tried to go in," Goeranzon said, adding that police also suspected the intruders had brought flammable liquids with them.

At one point, at least one of the men was hanging out the embassy window as rescue services scrambled to set up an inflatable mattress below, another police spokesman, Lennart Loefgren, told AFP earlier.

While it remained unclear why exactly the men had broken into the embassy, which was empty at the time except for one guard, Goeranzon said they had hung out the Libyan revolution flag on the embassy door.

Around 15 police patrols had immediately been sent to the scene and blocked off the embassy building and the surrounding area, and a number of fire trucks and ambulances also soon appeared.

According to Swedish media reports, a group of about 20 demonstrators standing outside the blocked-off area had began chanting "Libya" when police stormed the embassy.

Goeranzon said it was not yet clear if any of those arrested were Swedish nationals or residents.

Sweden in May expelled two Libyan diplomats accused of inappropriate activities, and while one Tripoli representative remained behind, Stockholm no longer has diplomatic ties with the mission.

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.