By Daren Butler
ISTANBUL (Reuters) - Turkish police detained more than 70 academics at an Istanbul university, NATO said Turkish soldiers had sought asylum and more pro-Kurdish mayors were arrested on Friday as a crackdown after July's failed coup entered its fifth month.
Some 110,000 people have been sacked or suspended in the civil service, army, judiciary and other institutions and 36,000 people jailed pending trial in the investigation of the abortive July 15 putsch, in which more than 240 people were killed.
Western allies, in particular in Europe, have voiced concern at the breadth of the purges under President Tayyip Erdogan. Some European politicians have called for a freezing of Turkey's EU membership talks, while a senior U.N. official on Friday described the measures as "draconian" and "unjustified".
Erdogan has repeatedly rejected such criticism, saying Turkey is determined to root out its enemies at home and abroad, and could reintroduce the death penalty. He has accused Western nations of siding with the coup plotters and harboring terrorists.
Istanbul prosecutors issued detention warrants for 103 teaching staff accused of "membership of an armed terror group" under an investigation into the city's Yildiz Technical University, one of the most prestigious education establishments so far affected, the state-run Anadolu agency said.
Police detained 73 of them in dawn raids, searching their homes and offices before taking them to hospital for routine health checks and then to the city's police headquarters.
Some were said to have been users of a smart-phone messaging app called ByLock, Anadolu said. The Turkish authorities say the app was used by followers of U.S.-based cleric Fethullah Gulen, blamed for masterminding the failed coup attempt.
Gulen denies involvement in the putsch.
Thousands of soldiers have been dismissed from the Turkish armed forces since the coup. NATO Secretary-General Jens Stoltenberg said on Friday some members of the military who were posted to NATO in Europe had requested asylum.
Speaking at a conference in Brussels, Stoltenberg stressed that Turkey remained a crucial NATO ally and that he condemned the July 15 putsch, but said Ankara must respect the rule of law.
"Some Turkish officers working in NATO command structures... have requested asylum in the countries where they are working," he said. "As always, this is an issue that is going to be assessed and decided by the different NATO allies."
Dozens of journalists in Turkey have also been jailed pending trial in the crackdown. U.N. Special Rapporteur on freedom of expression David Kaye voiced "deep concern" about widespread measures being used to erode free speech.
"Across the board, the government is imposing draconian measures that limit freedom of expression," Kaye said after a one-week official mission to Turkey.
He acknowledged the national security concerns faced by the government, but said: "The unjustified attacks on lawyers, judges, journalists, artists, academics and activists undermine security and generate polarization and long-term instability."
On Thursday, authorities dismissed 203 prosecutors and judges over links to what the government calls the "Gulenist Terror Group".
Parallel to the purges targeting alleged Gulen followers, authorities have been cracking down on politicians they accuse of ties to the Kurdistan Workers Party (PKK), designated a terrorist group by Turkey, the United States and the European Union.
A court on Friday sent the mayor of the southeastern city of Van, Bekir Kaya, to jail pending trial on a charge of aiding the PKK, a day after he was detained by police at the municipality building, party sources said.
Ankara has appointed administrators to run 34 municipalities, including the one in Van, to replace elected mayors from Kaya's pro-Kurdish Democratic Regions' Party (DBP).
Police on Friday detained another DBP mayor, Halis Coskun, who ran the council in the Malazgirt district of Mus province in eastern Turkey, the party sources said.
(Additional reporting by Tulay Karadeniz in Ankara, Robin Emmott in Brussels; Editing by Nick Tattersall and Janet Lawrence)