A woman stabbed and wounded six people in a bus in western Germany on Friday evening, police said. They had earlier said a total of five were injured in the incident but later revised the figure.

The 32-year-old suspect, a German national, was arrested after the attack in the town of Siegen.

At least 40 people were on the bus travelling to a city festival at the time of the incident.

Three of the victims are in a life-threatening condition, according to authorities.

Police are investigating the motive behind the crime. They said there were no indications that it was a terrorist attack.

Police appealed to citizens "not to spread false reports" on social networks or other channels.

Germany's Bild tabloid reported that the attacker may have been suffering from mental health issues.

Knife crime a growing security challenge

The incident comes a week after a deadly knife attack in Solingen that shook the country and forced the government to announce changes to security and asylum policies.

The Solingen attack left three people dead and eight wounded. The suspected perpetrator is a 26-year-old Syrian man who was previously due for deportation to Bulgaria.

Following the incident, Chancellor Olaf Scholz's government imposed new restrictions on carrying knives at public places. It also announced curbing benefits for some illegal migrants.

On Tuesday, police shot dead a man suspected of attacking passersby with knives in the western town of Moers near Solingen.