ISTANBUL (Reuters) -- Turkish authorities have formally arrested a senior army officer over possible links to an alleged right-wing group accused of plotting to topple the government, state-run news agency Anatolian said.
Lieutenant Colonel Mustafa Turkan Ecevit was arrested in Istanbul in connection with the discovery of a cache of weapons in the city including antitank weaponry, hand grenades and explosives. He was detained earlier this week.
Ecevit's arrest comes as part of a continuing probe into a shadowy ultranationalist group known as Ergenekon.
The investigation has seen retired senior military officers, lawyers and academics put on trial for planning to overthrow Prime Minister Tayyip Erdogan's government, eyed by some secularists as harboring an Islamic agenda.
Prosecutors say the alleged group was preparing a campaign of bombings and attacks which would create national chaos and force the armed forces to take control.
However, secularist critics say the plot amounts to little more than a crackdown on the government's opponents.
The widening investigation has threatened at times to unnerve markets in the European Union candidate country and has heightened tensions between the government and the country's traditionally powerful military.