A large-scale operation was carried out in downtown Athens on Thursday by Greek anti-terrorism police (Ε.Κ.Α.M).
The operation is still ongoing, but reports so far indicate that Ε.Κ.Α.Μ detained more than 20 people and seized heavy weaponry including anti-tank weapons.
A police statement said the individuals arrested in the raids that took place in two central Athens locations- Sepolia and Exarchia, were Kurds living in Greece.
The statement also noted that police discovered a secret tunnel in the house located in Sepolia, but provided no further information.
The operation is not connected with Islamic extremism, however authorities note that "the case is serious."