The three German citizens were detained at Istanbul's Ataturk international airport, Turkish media reported. They were alleged to have links to Anis Amri, the main suspect in the Berlin Christmas market attack.
All of those detained were German nationals of Lebanese origin, Turkey's state-run Anadolu news agency reported Monday.
They had been picked up last week on suspicion of having links to Anis Amri, the rejected Tunisian asylum seeker who investigators say drove a stolen truck into a crowded market in Berlin last December.
Media reports did not specify how the suspects arrested at Ataturk airport were connected to the attack in the German capital, but cited intelligence that said the three were headed to an unidentified European country. The reports added that one of the individuals had entered Turkey illegally and had allegedly been waiting to go to Europe with the intention of carrying out an attack.
Last year's Christmas market attack killed 12 people and left 56 others injured. Amri was killed several days later during a shootout with Italian police in Milan.
The "Islamic State" terror organization claimed responsibility for the attack. Amri had been under surveillance by German authorities for months.
A German citizen of Jordanian descent who also allegedly had ties to Amri was captured in the coastal city of Izmir earlier in March, Anadolu reported.
nm/kms (dpa, AFP)