Eighteen people were injured in a knife attack at the main railway station in the German city of Hamburg on Friday evening, police said.
Hamburg police said on Saturday that four of the victims who had sustained life-threatening injuries were in a stable condition.
Officers arrested a 39-year-old German woman at the scene of the attack, which took place at about 18:00 local time (16:00 GMT) on Friday.
Police said there was “very concrete evidence” of mental illness in the suspect, and no evidence the attack was politically motivated.
The woman remains in police custody and is scheduled to appear in court on Saturday.
The attack happened between platforms 13 and 14 – which are accessible via a busy main road – while a train was on one of the platforms.
The suspect began stabbing people waiting for the train, but was stopped by the “rapid intervention” of two people on the platform as well as emergency services, police said.
The victims range in age from 19 to 85. Seven people were slightly injured, seven seriously injured, and four critically injured, police said.
The critically injured – a 24-year-old female, 24-year-old male, 52-year-old female, and an 85-year-old female – were stable as of Saturday.
On Saturday police said there was still no evidence of a political motive for the attack.
“Rather, there is now very concrete evidence of a mental illness on the part of the suspect,” they said, adding that the woman did not appear to have been under the influence of drugs or alcohol.
An investigation is under way.
German Chancellor Friedrich Merz said the attack was “shocking” and thanked the emergency services for “their rapid assistance”.
Pictures from the scene on Friday showed emergency service personnel and vehicles and barriers that seem to be hiding the injured from public view.
A video on social media appears to show the suspect with her hands behind her back being escorted out of the station platform by officers who put her in a police vehicle.
Hamburg’s central station is one of Germany’s busiest transport hubs. It is often crowded during Friday rush hour.
This is the latest in a series of violent attacks in Germany in recent months.
In January, a two-year-old boy and a 41-year-old man were killed in a stabbing in a park in Aschaffenburg, with several others hurt.
A Spanish tourist was stabbed just a month later at Berlin’s Holocaust Memorial.
Last December, six people were killed and hundreds were injured after a car drove into a crowd at a Christmas market in the eastern city of Magdeburg.
The suspects in these previous attacks were migrants, which has led Germany to tighten border control checks and saw immigration become a key issue for voters during the country’s federal elections in February.
