A passenger was killed and three others were seriously injured after being attacked by a man with a knife on a commuter train at a station in Munich.

German forensicsA forensic expert of the police examines a commuter train standig on a platform of the train station of Grafing near Munich, southern Germany, where a man killed one person and wounded three others in a knife attack. Pic/AFP

The incident took place at Grafing S-Bahnhof in the suburban Ebersberg area of the city.

According to local media reports, the kinifeman had 'an apparent Islamist motive' as he screamed 'Allah hu Akbar' (God is greatest) during the attack.

Police said the man had slashed four people around 5am at the station in the town of Grafing east of Munich out of which one succumbed due to wounds.

The man has been arrested and the police spokesman said 'a political background cannot be ruled out,' adding that the man detained was 'not very cooperative'.

Further investigations are on.