Four men were charged under Norway's anti-terror law on Thursday after an attack on the Nordic nation's main synagogue, police said.
No one was injured in the attack, when one or more gunmen opened fire on the downtown Oslo synagogue before dawn Sunday. The front of the Mosaic Religious Community's building, which was empty at the time, was hit by at least 10 bullets.
The four men were arrested by police on Tuesday on charges of vandalism to a religious building. However, on Thursday Oslo police announced that the charge had been changed to organizing an act of terrorism.
"The men, who are between the ages of 20 and 30, in addition to firing on the Mosaic Religious Community synagogue or contributing to that are also charged under legal chapter 147a, covering terrorism," a police statement said.
Under that law, those planning or preparing an act of terrorism can face up to 12 years in prison if convicted. Police said they would seek a court order on Friday to hold the men in jail pending an investigation and possible indictment.
Police declined to release the names or other details of the suspects, other than to say that one was ethnically Norwegian, while the others had other backgrounds.
Nor would they say what evidence they had against the four.
"I can't comment on that ahead of the court hearing tomorrow on holding them in jail," Iver Stensrud, head of the Oslo police organized crime section, told the state radio network NRK.
The news media said one of the suspects was a 29-year-old Norwegian of Pakistani origin with a criminal history. The reports said he been briefly held in Germany in June on suspicion of planning an act of terrorism against the soccer World Cup. He was released without charges. He was also charged last week with firing gunshots at the home of a Norwegian journalist in Oslo earlier this year, the national news media said.
The attack on the synagogue shocked and angered Norwegians. On Monday, the Oslo bishop of the state Lutheran Church of Norway, Ole Christian Kvarme, urged Norwegians to rally around the country's tiny Jewish minority of about 1,300 people.
The Islamic Council in Norway and Inter-Church council also condemned the attack. Security around the synagogue was immediately stepped up.