Turkish police on Thursday detained about 10 people, mostly journalists, in a crackdown on an alleged secularist network accused of conspiring to topple the Islamic-rooted government, reports said. Critics say the case is part of a government assault on press freedom.

Police raided homes of suspects in Ankara and Istanbul, copied hard disks of their computers and seized notes or books that could serve as evidence in the case of the alleged Ergenekon network, NTV television said. Officials allege Ergenekon tried to overthrow Prime Minister Recep Tayyip Erdogan's Islamist government in 2003.

The raid on Thursday expanded a crackdown on anti-government Oda TV, with police detaining its coordinator Dogan Yurdakul along with several other journalists, NTV said. The United States expressed concern about press freedom in Turkey after a similar raid last month on Oda TV, prompting denials by Erdogan of any attempt to silence journalists.

The European Union and the Committee to Protect Journalists have accused Turkey of suppressing critical news and commentary on the alleged anti-government conspiracy. About 400 people, including journalists, politicians, academics and retired military officers are on trial, accused of being part of the alleged network.

The government insists the Ergenekon trials are a step toward democratic reform. Opponents counter that many of the accused are innocent and have been targeted as part of a broader plan to muzzle dissent and undermine Turkey's secular legacy.

Hundreds of journalists are being investigated for allegedly violating court rulings that bar media coverage of the case of Ergenekon, which takes its name from a legendary valley in Central Asia believed to be the Turks' ancestral homeland.

The alleged discovery during last month's raid of a computer file that focuses on the influence of an Islamic group within the police force, led police on Thursday to search the house of another journalist, Ahmet Sik, news outlets said.

Police would not comment.

Sik, a journalism professor at Bilgi University in Istanbul, is already on trial for a book he co-authored about the Ergenekon case. After the Oda TV raid, he had predicted a new police investigation against him, CNN-Turk television reported.

"I understand a copy of the book I am writing has seriously disturbed some people. That's why they are trying to link me with 'Ergenekon network,' via Oda TV," CNN-Turk television quoted Sik as saying Feb. 16 on the website Haber Vesaire.

Oda TV was raided after posting a video criticizing a police investigation into the alleged coup plot. The Istanbul-based Turkish Journalists' Association said the raid on Oda TV was the latest example of "intolerance" toward journalists. The owner of Oda TV, Soner Yalcin, and two of his colleagues have been jailed pending trial in the case.

Police on Thursday also raided the house of Nedim Sener, a leading investigative reporter for Milliyet and Sabah newspapers, on grounds that his name was mentioned in a document found on a computer of Oda TV.

Sener's neighbors hung red-and-white Turkish flags from their windows of their apartment building to protest the police raid.

A hardline secularist and leftist writer, Yalcin Kucuk, who often makes fiery statements against the government, was also among those detained on Thursday, NTV television said. Police also raided the home of a lawyer and a former intelligence officer with alleged ties to mobsters. The officer, Kasif Kozinoglu, was reported to be abroad.

Metin Feyzioglu, chairman of Ankara's Bar Association, said the law office of Kucuk's wife was also raided by police who ignored rules that a representative from the bar must be present.

"I say that is enough, enough of this injustice," Feyzioglu told reporters in reaction.