Swiss federal authorities have now called a recent stabbing at Winterthur train station an act of terrorism. The attack happened on Tuesday and left three people injured before police stopped and arrested the suspect. Officials explained this decision followed an early investigation into the attacker's reasons and actions.

The Swiss police and Attorney General's office are leading the investigation. The victims are in hospital, but their names are not public. Police are checking if the suspect acted alone or has any links to extremist groups.

Because of the new terrorism classification, Swiss officials have increased security across the country. There are more police at busy places like airports and train stations. The government has told people to stay alert, but says there is no sign of another threat at this time.