The offices of German Chancellor Angela Merkel have been sealed off after security officials found a suspicious package.
An image from the scene showed four yellow postal crates abandoned in heavy snow outside the chancellory in Berlin, with police sealing off the area while they assess the situation.
"We are investigating a suspicious package," a German police spokesman told Reuters, without elaborating on whether they planned to carry out a controlled explosion.
The German DPA news agency reported that the discovery had occured in the course of routine checks conducted on incoming parcel deliveries.
Federal police spokesman Thorsten Peters said the main entrance to the chancellery will remain sealed while authorities check the crates.
The chancellery itself wasn't evacuated and Merkel is due to lead a regular Cabinet meeting in the building later this morning.
The news comes amid ongoing threats of an Islamic State-inspired attack in a major German city.
On New Year's Eve police evacuated two train stations in the southern city of Munich after recieving intelligence suggesting up to seven suicide bombers were about to carry out a "serious imminent" attack.
Panic spread across the city, which was packed with millions of New Year's revellers, in the hours following the evacuation, although the stations reopened the following morning without any incident taking place.
German police maintain that the threat has not passed, however, and are understood to believe that any active terror cell could have moved on to another city in recent days.