Turkish and Greek security forces detained several suspected terrorists, including members of the Gülenist Terror Group (FETÖ) attempting to cross the border into Greece.

The intelligent units of the Greek police reportedly detained five FETÖ suspects who crossed the Maritsa River and arrived in Athens last month, reports said, adding that the suspects claimed they were members of FETÖ.

The Greek police also noted that they have found the passport information and photos of 500 individuals in the phones confiscated from the suspects.

They noted that the suspects were the main FETÖ members responsible for facilitating the transit of fugitive FETÖ suspects from Turkey to Europe.

Meanwhile, the Turkish Defense Ministry said border units have detained 12 terrorist suspects as they tried to cross into Greece from Edirne province.

The ministry said on Twitter: "12 individuals who had links to terrorist organizations and were attempting to cross into Greece from Edirne have been detained by our border units."

The statement did not specify which terrorist organizations the suspects were members of.

FETÖ suspects had become a major issue of contention between Turkey and Greece after the coup attempt.

Hours after the July 15, 2016, coup attempt failed, eight FETÖ-linked soldiers, including two commanders, four captains and two sergeants, escaped to Greece in a hijacked Sikorsky helicopter and landed in Alexandroupolis. Following their landing, the eight suspected FETÖ members asked for asylum from Greek authorities.

Before their asylum request was taken to court, a Greek court sentenced the eight men to a suspended two-month jail sentence for illegal entry into Greece.

Ankara formally requested from Greece the extradition of the FETÖ members who were behind the coup attempt to face trial in Turkey. Despite the Greek government's preference to extradite the eight suspects, the Greek judiciary has repeatedly denied the applications.

Led by U.S.-based imam Fetullah Gülen, FETÖ sought to topple the Turkish government and seize power on July 15, 2016, through a military coup and to impose martial law.

The attempt was prevented by military troops loyal to the government, along with police units and millions of Turkish citizens in favor of democracy.

In total, 251 people, mostly civilians, were killed by pro-coup soldiers, while over 2,000 people were injured.