Two people were killed and 14 others wounded, several seriously, in shootings in central Oslo, Norwegian police said Saturday.
Police said a suspect had been arrested following the shootings, which occurred around 1:00 am (2300 GMT Friday) in three locations close together in the center of the Norwegian capital.
Police reported two dead and 14 wounded, and said two weapons had been seized. "Now everything indicates that there was only one person who committed this act," police official Tore Barstad told a press briefing.
Police numbers had however been reinforced in the capital to deal with other incidents, he added, without wishing to specify whether it was a terrorist act.
Police received the first reports at 1:14 am and the suspect was arrested five minutes later, he said.
Heavily armed police equipped with bulletproof vests and helmets were patrolling the scene of the shootings.
"He looked very determined about where he was aiming. When I realized it was serious, I ran. There was a bleeding man lying on the ground," a woman who saw the incident told the Verdens Gang newspaper.
Another witness quoted by the paper mentioned the use of an automatic weapon -- which the police did not confirm -- and described it as "a war zone". "There were a lot of injured people on the ground who had head injuries," he said.
According to an NRK radio journalist present at the time of the shooting, the shooter arrived with a bag from which he pulled out a weapon and started firing.
Among the 14 wounded, eight were taken to hospital and six others were taken care of by a medical service. "Some are described as seriously injured, others as more lightly injured," said Barstad.
Norway was the scene of bloody attacks on July 22, 2011 when right-wing extremist Anders Behring Breivik killed 77 people.
He first detonated a bomb near the government headquarters in Oslo, killing eight people. He then disguised himself as a policeman and went on a shooting spree at a summer camp for left-wing youth on the island of Utoya, killing another 69 people -- most of them teenagers.