Last week police in neighboring Denmark charged two men suspected of detonating hand grenades near Israel's Copenhagen Embassy, while police in Sweden are investigating a suspected shooting near the Israeli diplomatic mission in Stockholm.
Norwegian police officers, who are normally unarmed, will now carry guns nationwide as a result of the decision by the PST security service to raise the threat level, the directorate said, Reuters reported.
"PST raises the terror threat level in Norway from moderate to high as a result of the ongoing escalation of the conflict in the Middle East," the police said in a statement.
The PST risk assessment was raised from level three (moderate) to level four (high), on PST's five-point scale where the top end of the range would indicate imminent danger.
National Police Commissioner Benedicte Bjoernland said there was an increased likelihood of attempted terrorism.
"...we have a number of measures in place to protect the population," she said in a statement.
MA/PR