TUNISIA (CBSNewYork/AP) — Tunisia’s Interior Ministry says police have arrested the nephew of Berlin Christmas market attacker Anis Amri and two others — and says all three men are suspected of belonging to a terrorist cell and had contacts with Amri.

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The ministry says the nephew, 18-year-old Fedi, told police he was in contact with Amri via Telegram’s encrypted communications to avoid detection. He told police that Amri had recruited him to jihad and asked him to pledge allegiance to IS. The nephew recorded such a pledge and sent it to Amri via Telegram.

He told police that Amri, using an alias, had sent his nephew money through the post office to join Amri in Germany to help him and join the Abou Walaa network. Amri told his nephew that he was the “emir” of the network.

The Tunisian prosecutor’s office has ordered all three men held in pre-trial detention pending further investigation.

Earlier this week, a video released by the Islamic State group showed Amri pledging allegiance to its leader Abu Bakr al-Baghdadi and vowing to fight against what he calls “the Crusader pigs.”

The video surfaced on the same day that 24-year-old Anis Amri was killed during a shootout with police in Italy, 600 miles from Berlin.

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Amri was the main suspect in the attack that killed 12 people and left 48 others injured.

On Saturday, about 200 people gathered at the Tunisian capital to protest against the return of Tunisian jihadis who have fought abroad.

Banners at the protest in front of Parliament in Tunis read “Close the doors to terrorism” and “No tolerance, no return.” Protesters waved Tunisian flags and sang the national anthem.

Protester Faten Mejri said “for us, they are not Tunisians. They are awful people.”

Tunisia says at least 800 Tunisian jihadis are under surveillance since returning home after fighting in Syria, Iraq and Libya.

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