A knife attack by a man reportedly shouting "Allahu akbar" that wounded three people at a Swiss train station was a "terrorist act", a regional security official has said.
"I am exceptionally calling this a terrorist attack," Mario Fehr, in charge of security in the Swiss canton of Zurich, told reporters, adding that it was "clear from the scene that the motive for this act must be sought in the realm of radicalisation and extremism."
Witnesses described scenes of panic and confusion when the man, who police said was a 31-year-old Swiss national, suddenly began stabbing people at the main train station in Winterthur - Switzerland's sixth largest city - during the morning rush hour.
"Shortly after 8.30am (7.30am Irish time) a man injured three people with a bladed weapon" at the station, police for Zurich canton said in a statement.
They said the suspected perpetrator had been arrested and that his "motive is under investigation".
Images broadcast by several Swiss media outlets and on social media showed a man with long dark hair and a full beard running in front of the station shouting "Allahu akbar!" (God is the greatest), while raising his right hand.
The three people who were injured in the attack were aged 28, 43 and 52 and were all Swiss citizens, police said, adding that all three had been taken to hospital.
Police spokesman Roger Bonetti told the SRF public broadcaster that one of the three had been seriously wounded.
A 65-year-old taxi driver named Turhan Muslu told the Blick newspaper that he witnessed the attack.
"I saw him rush off the ramp and try to stab a man," he told the daily, adding that the man had "fought back fiercely", before station guards arrived and subdued the attacker.
"It all happened so fast. If those security guards hadn't (arrived) so quickly, I don't know what would have happened."
In the published footage, filmed from a distance on a mobile phone, the man, wearing a black T-shirt and shorts, is seen running past a group of young children apparently on a school trip, without stopping.
"I heard a man scream 'Allahu akbar' five or six times, in a very agitated manner," a young man who witnessed the chaos that ensued told Blick, which did not provide his name.
The witness described how the young children and other bystanders had "run across the road" in panic.
"Thinking back on it, I still have goosebumps," he said.
Attacks targeting random passers-by are rare in Switzerland, and people in the city, located 25kms northeast of Zurich, voiced shock at what had unfolded.
"This is not OK. We want peace," Basharat Iqbal, a taxi driver who arrived at the station after the attack, told AFP.
"I was shocked."
The Zurich cantonal police force said it was cooperating with Winterthur municipal police, the Swiss Federal Railways' transport police, and hospital, ambulance and rescue services in the operation.
At the scene, several police cordons were deployed at various locations inside and outside the station, according to images published by local media.
The attack did not cause any disruption to train traffic, Swiss Federal Railways said.
