Sweden iStock

A predawn raid on two suspected Russian spies took place in the Stockholm area on Tuesday.

Swedish officials revealed little about the arrests. However, local media interviewed witnesses who said that they observed elite tactical law enforcement teams rappelling from two helicopters to place the couple in custody, the Associated Press reported.

The Swedish Prosecution Authority announced that one of the suspects was being charged with “gross illegal intelligence activities against Sweden and against a foreign power.” The foreign power referred to was not identified.

The operation was a joint operation of the police and military whose helicopters were used. Sweden’s security agency said it involved house searches and had been a long term investigation.

According to the Aftonbladet newspaper, the suspects are a Russian couple in the sixties who have been living in Sweden since the late 1990s.