OSLO, April 9 (Xinhua) -- Norway has decided to raise the country's threat level after a homemade explosive device was found in central Oslo and a teen asylum seeker from Russia was charged, the police security service (PST) said on Sunday.
The Norwegian police raised the country's threat level to "probable" from "possible," which is valid for two months, PST head Benedicte Bjornland told a press conference.
"The Joint Counter Terrorism Center has until today considered it possible that there will be a terrorist attack against Norway in 2017," Bjornland said. "Recent developments have created a number of points of uncertainty which implies that the assessment should be upgraded to be probable."
"It is likely that the attacks on France, Germany, Britain, Russia and Sweden create a contagious effect to people inside Norway with extreme Islamist sympathies," she said.
Norway's Police Directorate said later that police in major cities and at Oslo Gardermoen Airport had been allowed to temporary armament and their presence had also been increased after the attack in Stockholm, Sweden, Friday.
The directorate said it is not necessary to take further measures beyond those which were implemented Friday as they already "compensate for the elevated threat level as the PST set."
The 17-year-old Russian citizen, who came to Norway as an asylum seeker in 2010, has been charged with illegal dealings with explosive material, PST police attorney Signe Aalling said at the same press conference.
The Russian young man was taken into police custody with a bomb-like object in Oslo's Gronland area late Saturday. Police carried out a controlled explosion of the object early Sunday after a large area was cordoned off.
The PST, which had taken over the investigation from local police after the controlled explosion, said that the bomb-like object was a primitive improvised explosive charge with limited damage potential.
"It is unclear whether the 17-year-old had intentions to carry out a terrorist attack," Bjornland said.
It remained unclear whether more people were involved in the incident. The Russian man was arrested after a passerby contacted police because he perceived the man as suspicious, according to Norwegian newspaper VG.
The Russian asylum seeker does not admit guilt, according to his lawyer Aase Karine Sigmond.
"He is opposed to the police saying that he should have planned a terrorist attack. He is opposed to the Islamic State (IS)," Sigmond told VG.
The cordon was lifted early Sunday and the Gronland area resumed normal activities during the day.
The incident came just one day after a truck ploughed into pedestrians on a busy shopping street before crashing into a department store in central Stockholm, Sweden, killing four people and wounding many others.