Turkey vowed to root out allies of the U.S.-based cleric it blames for an abortive coup last week, widening a purge of the army, police and judiciary on Tuesday to universities and schools, the intelligence agency and religious authorities.
Around 50,000 soldiers, police, judges, civil servants and teachers have been suspended or detained since the coup attempt, stirring tensions across the country of 80 million which borders Syria's chaos and is a Western ally against Islamic State.
"This parallel terrorist organization will no longer be an effective pawn for any country," Prime Minister Binali Yildirim said, referring to what the government has long alleged is a state within a state controlled by followers of Fethullah Gulen.
"We will dig them up by their roots," he told parliament.
A spokesman for President Tayyip Erdogan said the government was preparing a formal request to the United States for the extradition of Gulen, who Turkey says orchestrated the failed military takeover on Friday in which at least 232 people were killed.
U.S. President Barack Obama discussed the status of Gulen in a telephone call with Erdogan on Tuesday, the White House said, urging Ankara to show restraint as it pursues those responsible for the coup attempt.
In parallel talks, U.S. Defense Secretary Ash Carter and his Turkish counterpart discussed the importance of Turkey's Incirlik Air Base in the campaign against Islamic State in Syria and Iraq, the Pentagon said.
The base, which is used by Turkish and U.S. forces in the air campaign against Islamic State, has been without power in the days since the failed coup.
Seventy-five-year-old Gulen, who lives in self-imposed exile in Pennsylvania but has a network of supporters within Turkey, has condemned the abortive coup and denied any role in it.
A former ally-turned critic of Erdogan, he suggested the president staged it as an excuse for a crackdown after a steady accumulation of control during 14 years in power.
On Tuesday, authorities shut down media outlets deemed to be supportive of the cleric and said 15,000 people had been suspended from the education ministry along with 100 intelligence officials. A further 492 people were removed from duty at the Religious Affairs Directorate, 257 at the prime minister's office and 300 at the energy ministry.
The lira weakened to beyond 3 to the dollar after state broadcaster TRT said all university deans had been ordered to resign, recalling the sorts of broad purges seen in the wake of successful military coups of the past.
In a sign of international concern, a German official said a serious fissure had opened in Turkey and he feared fighting would break out within Germany's large Turkish community.
"A deep split is emerging in Turkish society," Bavarian Interior Minister Joachim Herrmann told the Berliner Zeitung newspaper. "The danger of an escalation in violence between Erdogan supporters and opponents has also risen in Germany.""DOUBLE STANDARDS"
Turkey's Western allies have expressed solidarity with the government over the coup attempt but also alarm at the scale and swiftness of the response, urging it to adhere to democratic values.
Prime Minister Yildirim accused Washington, which has said it will consider Gulen's extradition only if clear evidence is provided, of double standards in its fight against terrorism.
Yildirim said the justice ministry had sent a dossier to U.S. authorities on Gulen, whose religious movement blends conservative Islamic values with a pro-Western outlook and who has a network of supporters within Turkey.
"We have more than enough evidence, more than you could ask for, on Gulen," Justice Minister Bekir Bozdag told reporters outside parliament. "There is no need to prove the coup attempt, all evidence shows that the coup attempt was organized on his will and orders."
White House spokesman Josh Earnest confirmed Ankara had filed materials in electronic form with the U.S. government, which officials were reviewing. Any extradition request from Turkey, once submitted, would be evaluated under the terms of a treaty between the two countries, he added.
This treaty excludes offences "of a political character" although it does cover those "committed or attempted against a head of state or a head of government".
Any extradition request would face legal and political hurdles in the United States. Even if approved by a judge, it would still have to go to Secretary of State John Kerry, who can consider non-legal factors, such as humanitarian arguments.
"I urge the U.S. government to reject any effort to abuse the extradition process to carry out political vendettas," Gulen said on Tuesday in a statement issued by the Alliance for Shared Values, a group associated with the cleric.