An Afghan teenager was arrested on Sunday in Germany on suspicion that he was connected to Friday’s mass attack in Munich, police said.

The 16-year-old male may have known about the plans of the gunman, who killed nine people, but the teen did not tell authorities, officials said. The teen is also suspected of having played a role in a Facebook post that invited the public to a location near where the deadly shooting later took place, Reuters reported.

“There is a suspicion that the 16-year-old is a possible tacit accomplice to [Friday’s] attack,” a police statement said.

Further details were not immediately available, but Germany's dpa news agency reported the 16-year-old teen had gone to police himself after the act.

The gunman in the Munich assault was identified as an 18-year-old Iranian-German.

The Associated Press contributed to this report.