Teenage friend of Munich gunman arrested: police

German police said on Sunday they had arrested a 16-year-old Afghan friend of the gunman who killed nine people in a rampage at a shopping centre in Munich.

"We suspect that this boy aged 16 years could have been aware of the act," police said in a statement following Friday's shooting spree after which the 18-year-old German-Iranian gunman killed himself.

The arrest is the first in the investigation.