Barriers to prevent vehicles ramming into crowds are laid out at the main shopping avenue, Karl Johan street, in Oslo, Norway November 7, 2017. REUTERS/Joachim Dagenborg

OSLO (Reuters) - Norwegian police said on Wednesday they had lowered the national threat assessment, but still regarded an attack by militants as a possibility.

The risk level was lowered to “possible” from “likely”, reversing an April decision to raise the threat assessment following an Oslo bomb scare and an attack in neighboring Sweden, where four people were killed.