A 16-year-old Afghan youth has been arrested by German police on suspicion of a connection to the killing of nine people by an 18-year-old gunman in Munich.
The youth was under investigation for possibly having failed to report the plans of the gunman, who later shot himself, and may have played a role in a Facebook posting that invited people to the scene of the shooting, a police statement said on Sunday (local time).
"There is a suspicion that the 16-year-old is a possible tacit accomplice to (Friday's) attack," it said.
Police earlier said the gunman was a deranged Iranian-German who was fixated with mass killings but not inspired by Islamist militancy.
The teenager had been planning the attack for a year, police say.
According to prosecutor Thomas Steinkraus-Koch, the gunman, who German media named as Ali David Sonboly, was not motivated by a political ideology and chose his victims randomly.
Six of the nine victims had a non-German heritage, police said earlier on Sunday. They included three 14-year-olds, two 15-year-olds, and four others aged 17, 19, 20 and 45.
The Bavarian State Crime Office said Sonboly, 18, had bought the illegal pistol used in the attack on the internet.
Police on Sunday raised the number of people injured in Friday's rampage from two dozen to 35.
Bavaria's interior minister Joachim Herrmann told broadcaster B24 the German-Iranian teenager had a copy of the manifesto of Norway attacker Anders Breivik saved on his computer and travelled "within the past two years" to the scene of a 2009 school shooting in the southern German town of Winnenden.
Steinkraus-Koch said Sonboly spent two months in a closed psychiatric ward in 2015 and received treatment for "social phobias" and anxiety.
"The suspect had fears of contact with others" and also depression, he said.
The shooter took his own life following the attack.
Robert Heimberger, president of the Bavarian state criminal agency, said the parents of the gunman remained in shock and were not able to be interviewed.
He said Sonboly was a keen player of "first-person shooter" video games.
Heimberger said there is still no evidence of any political motivation to the crime, nor that the shooter killed specific victims.
Vigils continue in the Bavarian capital to commemorate the victims, seven of whom were teenagers.
Three were from Kosovo, three from Turkey and one from Greece.
Reuters / DPA