One person has been killed and three injured in a knife attack at a train station near Munich.

Witnesses said that the suspected attacker shouted "Allahu Akbar" - Arabic for "God is great" - during the stabbings, but police say there is no evidence he was part of an Islamic extremist network.

The man was arrested shortly after the attack in Grafing at around 4:50am local time. Officials have said that the 27-year-old, named locally as Paul H., has "mental health and drug problems," according to AFP.