The nephew of Anis Amri, the suspect killed in a shootout with police on Friday after killing 12 people and injuring dozens more at a Berlin market, has been arrested in Tunisia, the country's Interior Ministry said Saturday.
He is one of three men being held in prison on "suspicion of belonging to a terrorist organization and connections with terrorist offenses," according to the ministry.
Officials say the nephew used an app to communicate with Amri.
This is the latest-known update on the Berlin attack investigation.
The Tunisian interior ministry said the three men were members of a "terrorist cell," and that the men were detained overnight.
The statement added that the nephew had also said he supported the so-called Islamic State group.
Police are still searching for possible accomplices.
--This story is developing.