Hamburg’s fire brigade has issued an “extreme danger” alert as a cloud possibly containing “chemical components” drifts towards the city centre.
The German city’s authorities are advising people to avoid the area and told residents to close doors, windows and ventilation.
It comes after a fire at a storage facility in the Rothenburgsort district that forced 140 people to evacuate.
Police say it is not possible to say how dangerous the situation is.
Multiple police, fire and other emergency workers were at the scene as a thick cloud of smoke billowed upwards.
There are no reports of any casualties.
Local public broadcaster NDR reported that the fire broke out at 4.30am at a truck stop.
‘Extreme danger’
A spokesman for the fire brigade told NDR that Hamburg city center was “completely blacked out,” when the fire broke out.
In an official warning published by Hamburg police, it said the smoke development was classified as “extreme danger” and recommended residents to avoid the affected area and to “drive around the affected area as far as possible.”
It has also issued a warning for people to close windows and doors and has told residents to pay close attention to loudspeaker announcements.
On Sunday morning the national railway company Deutsche Bahn also announced its closure between Hamburg and Büchen due to the fire.
The railway said trains between Hamburg and Berlin will be diverted and delayed by around 90 minutes.
Photos at the scene show the storage facility engulfed in smoke and flames.
