Seven people were arrested in Denmark on suspicion of attempting to make explosives and planning terrorist attacks, police said, after a joint law enforcement operation between Demark and Germany.
Those arrested are alleged to have acquired ingredients and components for manufacturing explosives and firearms.
"We believe that there are individuals with the intent and capacity to commit terrorist attacks in Denmark," Danish police said in a statement late on Thursday.
Six others were arrested in Denmark and one person in Germany in connection with the same case, they said.
Danish police are scheduled a press briefing at 1000 GMT on Friday.