ATHENS, Greece — Greek police on Wednesday said they will demand that terrorism-related charges be brought against three Greeks and three Turks arrested for allegedly trying to ferry weapons and explosives in a speedboat to Turkey.

Greek authorities say they are investigating whether the Turks are involved in militant activities in Turkey, and a Turkish official alleged that one is a member of an outlawed leftist group that used a suicide bomber to attack the U.S. Embassy in Ankara in February.

Four of the suspects were arrested Tuesday near the Aegean Sea island of Chios, after coast guards intercepted their boat.

Officials said two anti-tank weapons, two pistols, four hand grenades, bullets and improvised explosive devices were found on board. Another two men were arrested later Tuesday on Chios.

All six were to be taken to a Chios prosecutor late Wednesday, under strict security measures.

Counterterrorism police also raided homes and offices in Athens, Thessaloniki and Corinth on Tuesday, and arrested two foreign nationals on allegations of possession of forged identity papers. Another 12 people were detained and then released without charges.

Greek authorities have not released the identities of any of the suspects.

But Turkish Interior Minister Muammer Güler said one of the three Turkish men detained Tuesday was Hasan Biber, accused of involvement in two attacks in Ankara in March, according to the state run Anatolia news agency.

He said Wednesday that Biber is a member of the outlawed leftist Revolutionary People's Liberation Party/Front (DHKP-C), which has claimed responsibility for the embassy attack.

DHKP-C has carried out assassinations and bombings since the 1970s, but has been relatively quiet in recent years. It is considered a terrorist organization by Turkey, the United States and the European Union.