German police have said they had arrested a woman after at least 12 people were injured in a knife attack at the main station in the northern city of Hamburg.
Some of the injured sustained life-threatening injuries in the stabbing, emergency services said, although the exact number remained unclear.
Around 6.30pm local time (5pm Irish time), Hamburg police said on X they were carrying out a major operation at the main train station in Germany's second-largest city.
"A person injured several people with a knife at the main train station" and a suspect had been arrested, they said.
The suspect, police subsequently said, was a 39-year-old woman who was thought to have "acted alone".
Investigations into the incident were "running at full speed", police said, without giving an indication of a possible motive.
A spokesman for the Hamburg fire department said that 12 people had been injured in the knife attack.
Among them were "six people with life-threatening injuries", the spokesman said. German media however reported the number of people with very severe injuries was lower.
Security concerns
The attack took place in the middle of rush hour at the end of the working week, according to German media.
The suspect was thought to have carried out the attack "against passengers" at the station, a spokeswoman for the Hanover federal police directorate, which also covers Hamburg, said.
Images of the scene showed access to the platforms at one end of the station blocked off by police and people being loaded into waiting ambulances.
Some of the victims in the attack were being treated onboard waiting trains in the station, Bild reported.
German rail operator Deutsche Bahn said on X that four platforms at the station had been closed.
Germany has been rocked in recent months by a series of violent attacks with often jihadist or far-right extremist motivations that have put security at the top of the agenda.
The most recent, on Sunday, saw four people were injured in a stabbing at a bar in the city of Bielefeld.
The investigation into the attack had been handed over to federal prosecutors after the Syrian suspect in the attack told the police officers who arrested him that he had jihadist beliefs.
The question of security - and the immigrant origin of many of the attackers - was a major topic during Germany's recent election campaign.
The vote at the end of February saw the conservative CDU/CSU top the polls and a record score of over 20 percent for the far-right, anti-immigration Alternative for Germany.
