ISTANBUL (Reuters) - Turkish authorities released 160 construction workers who had demonstrated against labour conditions at Istanbul's new airport, but hundreds are still detained and protests are likely to continue, a union leader said on Sunday.
The airport, a centrepiece of a 15-year construction boom under Turkish President Tayyip Erdogan, is due to open late next month.
Unions say workers at the site have long complained about conditions, including pay, food and living quarters, as well as safety standards. Protests broke out on Friday after a shuttle bus accident injured 17 workers.
Thousands of workers joined the demonstration, which was broken up by police who deployed in riot control vehicles and detained 500 people, one union leader said.
Video footage, which the union said was from the construction site, showed hundreds of men chanting: "We are workers, we are right, we will have our way one way or another."
Large labour protests have been rare in Turkey since a state of emergency was imposed following a failed July 2016 coup. It was lifted two months ago after Erdogan's re-election but his opponents say Turkey's new executive presidency retains many of the emergency powers.
Ozgur Karabulut, general manager of Dev Yapi-Is union, said on Sunday that 160 people had been released and the union estimated 360 remained in detention.
"Some of our friends who were released last night were taken back to the camps but they are not working," he told Reuters. "We expect these protests to go on for a long time."
A statement issued on Sunday by unions complained of late salary payments, poor food and "awful" conditions at the workers' living quarters. The "airport construction site is no different to concentration camp for workers," it said.
The unions said they would continue to fight until working conditions were improved and the detained workers were released and allowed to resume their jobs.
While the airport is scheduled to open at the end of October, Karabulut said that was in doubt because the remaining work would take another two months.
An official at airport operator IGA played down the protests, saying work continued and the airport would open as planned on Oct. 29.
"Our workers are working to schedule, there is no disruption at all," IGA's corporate communications director Gokhan Sengul said. "There was a little bit of protests on Friday triggered by provocateurs who came in on Friday like union representatives."
Sengul said the company had already started improvements, including disinfecting rooms and laying on extra buses to prevent delays to and from work.
"All this talk about protests is just manipulation... We are due to open on October 29 with no disruption," he said.
(Writing by Dominic Evans; Editing by Susan Fenton)