ISTANBUL/ANKARA (Reuters) - Turkey purged its police on Monday after rounding up thousands of soldiers in the wake of a failed military coup, and said it could reconsider its friendship with the United States unless Washington hands over a cleric Ankara blames for the putsch.

Nearly 20,000 members of the police, civil service, judiciary and army have been detained or suspended since Friday night’s coup, in which more than 200 people were killed when a faction of the armed forces tried to seize power.

The broad crackdown and calls to reinstate the death penalty for plotters drew concern from Western allies who said Ankara must uphold the rule of law in the country, a NATO member whose cooperation in the fight against Islamic State is crucial to Washington.

Some voiced concern President Tayyip Erdogan - who said he was almost killed or captured by the mutineers - was using the opportunity to consolidate his power and further a process of stifling dissent which has already caused tensions with Europe.

Turkey’s foreign ministry said criticism of the government’s response amounted to backing for the bid to overthrow it.

A senior security official told Reuters that 8,000 police officers, including in the capital Ankara and the biggest city Istanbul, had been removed from their posts on suspicion of links to Friday’s abortive coup.

About 1,500 finance ministry officials had been suspended, a ministry official said, and CNN Turk said 30 governors and more than 50 high-ranking civil servants had been dismissed. Annual leave was suspended for more than 3 million civil servants, while close to 3,000 judges and prosecutors have been suspended.

Prime Minister Binali Yildirim said 7,543 people had so far been detained, including 6,038 soldiers. Some were shown in photographs stripped to their underpants and handcuffed on the floors of police buses and a sports hall. A court remanded 26 generals and admirals in custody on Monday, Turkish media said.

Officials in Ankara say former air force chief Akin Ozturk was a co-leader of the coup. The state-run Anadolu agency said on Monday he had confessed, but private broadcaster Haberturk contradicted this, saying he had told prosecutors he tried to prevent the attempted putsch.

The Turkish government says it was masterminded by Fethullah Gulen, a Muslim cleric based in the United States who has a wide following in Turkey. He denies any involvement.

Ankara has demanded Washington hand Gulen over, and Erdogan told international broadcaster CNN on Monday that an extradition request would be filed this week. Washington says it is prepared to extradite him but only if Turkey provides evidence linking him to crime. Yildirim rejected that demand.

“We would be disappointed if our (American) friends told us to present proof even though members of the assassin organisation are trying to destroy an elected government under the directions of that person,” Yildirim said.

“At this stage there could even be a questioning of our friendship.”.

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Yildirim said 232 people were killed in Friday night’s violence, 208 of them civilians, police and loyalist soldiers, and a further 24 coup plotters. Officials previously said the overall death toll was more than 290.

Around 1,400 others were wounded as soldiers commandeered tanks, attack helicopters and warplanes in their bid to seize power, strafing parliament and the intelligence headquarters and trying to seize the main airport and bridges in Istanbul.

Erdogan’s decision to allow the resumption of flights at the Incirlik Air Base, which hosts a number of U.S. intelligence facilities and plays a strategic role in the fight against Islamic State militants, has averted an immediate confrontation between the two allied countries.

But U.S. officials have been rattled by the extent of Turkey’s response to the failed coup and say the relationship will now depend on how Erdogan pursues Gulen and how far the crackdown extends.

Significantly, the commander of Incirlik, General Bekir Ercan Van, was among those detained over the abortive coup.

“We believe Turkey has gone beyond what we wanted to see,” said one U.S. official, speaking on condition of anonymity.

ERDOGAN: I WOULD HAVE BEEN KILLED

The coup crumbled after Erdogan, on holiday with his family at the coastal resort of Marmaris, phoned in to a television news programme and called for his followers to take to the streets. He was able to fly into Istanbul in the early hours of Saturday, after rebel pilots had his plane in their sights but did not shoot it down.

He said on Monday that he might have died if he had left Marmaris any later. “Two of my close bodyguards were martyred, they were killed,” he told CNN in an interview. “Had I stayed 10 or 15 additional minutes there, I would have been killed or I would have been taken.”

He repeated his call that parliament must consider his supporters’ demands to apply the death penalty for the plotters.

“The people have the opinion that these terrorists should be killed,” he said. “Why should I keep them and feed them in prisons for years to come, that’s what the people say.”

Turkey gave up the death penalty in 2004 as part of a programme of reforms required to become a candidate to join the EU. German Chancellor Angela Merkel said reinstating it would “in no way” be compatible with Turkey’s goal of EU membership.

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The bloodshed shocked the nation of almost 80 million, where the army last used force to stage a successful coup more than 30 years ago, and shattered fragile confidence in the stability of a NATO member state already rocked by Islamic State suicide bombings and an insurgency by Kurdish militants.

Since the coup was put down, Erdogan has said enemies of the state still threatened the country and has urged Turks to take to the streets every evening until Friday to show their support for the government.

Thousands heeded his words and took to squares in Turkey’s three biggest cities on Monday, the third day in a row, to show their support.

Western countries said they supported Erdogan’s government but Ankara should abide by the rule of law.

“We stand squarely on the side of the elected leadership in Turkey. But we also firmly urge the government of Turkey to maintain calm and stability throughout the country,” U.S. Secretary of State Kerry told a news briefing in Brussels where he attended a gathering of European counterparts.

“We will certainly support bringing the perpetrators of the coup to justice but we also caution against a reach that goes well beyond that.”

Referring to Gulen, Kerry called on Turkey to furnish evidence “that withstands scrutiny”, rather than allegations.

EU foreign policy chief Federica Mogherini also called on Ankara to avoid steps that would damage the constitutional order.

Turkey’s pro-Kurdish HDP opposition, parliament’s third largest party, said it would not support any government proposal to reintroduce the death penalty. The main CHP opposition said the response to the coup attempt must be conducted within the rule of law and that the plotters should face trial.

‘HEAVY BLOW’ TO MILITARY

Turkish security forces are still searching for some of the soldiers involved in the coup bid in various cities and rural areas but there is no risk of a renewed bid to seize power, a senior security official told Reuters.

The official said Turkey’s military command had been dealt “a heavy blow in terms of organisation” but was still functioning in coordination with the intelligence agency, police and the government. Some high-ranking military officials involved in the plot have fled abroad, he said.

Erdogan has long accused Gulen of trying to create a “parallel state” within the courts, police, armed forces and media. Gulen, in turn, has said the coup attempt may have been staged, casting it as an excuse for Erdogan to forge ahead with his purge of the cleric’s supporters from state institutions.

The swift rounding up of judges and others indicated the government had prepared a list beforehand, the EU commissioner dealing with Turkey’s membership bid, Johannes Hahn, said.

“I’m very concerned. It is exactly what we feared,” he said in Brussels.