A woman stabbed and wounded five people in a bus in western Germany on Friday, police said, one week after a deadly knife attack that shook the country.

The 32-year-old suspect was arrested after the incident in the town of Siegen with no indications it was a terrorist attack, the local police force said in a statement.

Three of the five victims are in a life-threatening condition, one is seriously wounded and the fifth only lightly injured.

Germany was rocked by a stabbing attack one week ago that left three people dead and eight wounded in the western city of Solingen.

The identity of the suspected attacker, a 26-year-old Syrian man who was previously due for deportation to Bulgaria, stoked debate about Germany's immigration and asylum policies.

The killings have prompted Chancellor Olaf Scholz's government to announce new restrictions on carrying knives at public gatherings and on long-distance transport, as well as curbing benefits for some illegal migrants.

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