Greek counter-terrorism officers stormed three buildings in Athens on Tuesday making nine arrests.
The raids at Neos Kosmos and Pagrati targeted suspects wanted on terrorist charges in Turkey.
Greek media speculate that the raids targeted suspected members of the outlawed Kurdish group DHKP-C.
“So far nine people have been detained, they are Afghans and Kurds based on their identity papers. Police found jars containing unspecified explosive material, cables to connect to detonators and laptops,” a police official told Reuters.
A second police official confirmed authorities were probing links to DHKP/C, an outlawed group blamed for attacks and suicide bombings in Turkey.
Turkish President Tayip Erdogan is expected to visit Greece in December.