Hawzah News Agency (Ankara, Turkey) - A statement from the Ankara chief prosecutor's office said the suspects were nabbed in a police operation on Monday.

It said all the suspects are foreigners, without providing detail on their nationalities. 

According to the statement, they are suspected of trying to recruit members for the extremist group and were allegedly in contact with people in "conflict zones."

The detentions came as the US Embassy in Ankara was closed on Monday due to an unspecified security threat.

A statement posted on the embassy's web page urged US citizens to avoid the embassy in Ankara as well as large crowds and to "keep a low profile."