This year's Nobel laureates, including a pro-democracy Tunisian group, will get their prizes on Thursday in Oslo and Stockholm, with security at the lavish banquets and concerts tightened after the Paris attacks last month.
Tunisia's National Dialogue Quartet won the peace prize for helping to build democracy in the birthplace of the Arab Spring, an example of peaceful transition in a region struggling with violence and upheaval.
"Security is higher than it would otherwise have been because of the situation in Europe," Johan Fredriksen, chief of staff for Oslo police told Reuters.
Fredriksen declined to go into specifics. He said there were no specific threats the police were aware of in Norway.
Last year, a demonstrator carrying a Mexican flag disrupted the Nobel ceremony at Oslo City Hall when Pakistani teenager Malala Yousafzai and Indian activist Kailash Satyarthi received their Nobel Peace Prizes. He was not a guest but managed to get through the security checkpoints.