AN axe-wielding attacker suffering from mental health problems injured seven people at the main train station in the German city of Dusseldorf late Thursday (local time), police told AFP.

Previously police had said several attackers were involved and two were arrested but they later said one suspect was behind the assault, a 36-year-old man from the former Yugoslavia.

“An assailant probably armed with an axe attacked people at random” at about 8.50pm local time,” city police said in a statement.

Police initially gave the number of injured as five, but updated that to seven in a later statement.

While trying to escape the man jumped from a bridge and suffered serious injuries from the fall, the statement said.

He was not in a position to be interrogated, German news agency DPA reported.

Large numbers of police, including special units, were deployed at the station and traffic was halted. Bild newspaper reported that helicopters flew overhead.

“Interruption at the central station in Dusseldorf. We can’t say when the trains will start running again,” regional police said on Twitter.

An axe was recovered and officers were searching the area in and around the station, which was closed for the investigation.

Federal police spokesman for the regional state of North Rhine-Wesphalia state, Rainer Kerstiens described the attack to Deutsche Welle as an “amok attack.”

A station attendant told Bild: “We were standing on the track, waiting for the train. The train came, and suddenly someone jumped out with an axe, hit the people. There was blood everywhere. I have experienced a lot, but I have never experienced this.”

An image posted on Twitter shows what appears to be injured passengers lying on the station floor surrounded by emergency services personnel.

Terrified passengers have taken to social media to say the situation inside the station “looks bad”.

Bruno Macedo tweeted: “Man with axe chased by police in Dusseldorf. Station closed. I am in the train things look bad #police #terror.’

He also posted a video on Facebook of himself and other passengers in lockdown inside a train carriage at the stop before Dusseldorf.

“So apparently there is a crazy guy with an axe,”Macedo says in the video.

“We just got a warning and things are getting worse apparently.”

Peter Altmaier, a close adviser to Angela Merkel, wrote on Twitter: “What happened at the central station in Dusseldorf, our compassion and our thoughts go out to the injured.”

Thomas Geisel, city mayor, also reached out to victims, according to Bild.

“It’s a huge blow for Dusseldorf. Many people are in shock. I’d like to thank the police. My thoughts go out to the victims and their families,” he said.

German authorities have been on alert for terror attacks, especially since an assault claimed by the Islamic State terror group in December when a hijacked truck ploughed into a Berlin Christmas market, killing 12 people.

According to German security services, there are about 10,000 radical Islamists in the country, of whom 1600 have suspected links to terror groups.

There was another axe attack on a train in 2016 in Germany’s Bavaria, but no-one was killed and the attacker was found to be mentally unbalanced.