A HAND-PAINTED flag of the Islamic State group has been found among the belongings of the 17-year-old Afghan refugee who attacked train passengers with an axe and a knife, the interior minister of the southern state of Bavaria told German television.

The flag was found in the room of the man who seriously wounded four people and injured several others on a regional train in the city of Wuerzburg, the minister, Joachim Herrmann, said on ZDF public television.

The teenager was shot dead by police as he tried to flee.

Three people are in a critical condition and several others were injured in the assault on a regional train near the southern city of Wuerzburg.

“It is quite probable that this was an Islamist attack,” said a ministry spokesman, adding that the assailant had shouted “Allahu akbar” (God is greatest).

Blood stains are seen in the train carriage. Source: Apexchange

However he stressed that the investigation was ongoing and that the teenager appeared to have acted alone.

An eyewitness who lives next to the railway station told DPA news agency that the train, which had been carrying around 25 people, looked “like a slaughterhouse” with blood covering the floor.

The man, who declined to give his name, said he saw people crawl from the carriage and ask for a first-aid kit as other victims lay on the floor inside.

“The perpetrator was able to leave the train, police left in pursuit and as part of this pursuit, they shot the attacker and killed him,” a police spokesman said.

© AFP, 2016