Turkish state media say police have arrested around 30 more people connection with an alleged plot to bring down the Islamic-rooted government.
The Anatolia news agency says army and police officers, a journalist, and the leader of a metal workers union were among those detained during police raids in 13 provinces on Thursday.
Authorities were also said to be searching the union's office and an opposition television station. Turkish prosecutors say the searches could lead to more arrests.
In Ankara, Prime Minister Recep Tayyip Erdogan met with the country's top military commander, General Ilker Basbugm on Thursday to discuss the investigation.
Eighty-six people are already on trial over their suspected links to the ultra-nationalist organization Ergenekon, which is accused of plotting to topple the government.
Opposition leaders accuse the ruling AK party of deliberately targeting secularists, including Turkey's military, who they say oppose the government's efforts to raise the profile of Islam.