Seven workers seized at a Proctor & Gamble (P&G) plant outside the Turkish city of Istanbul were rescued after a nine-hour ordeal, officials say.
Police in Gebza moved in after the suspect, who was apparently protesting at the war in Gaza, went to the toilet.
Local governor Seddar Yavuz said the hostages had suffered no injuries.
Images online showed the suspect, his face hidden by a Palestinian scarf, wearing what appeared to be an explosives vest and carrying a gun.
He was detained unharmed after the “meticulous” rescue operation, Mr Yavuz added.
The hostage-taker entered the plant at about 15:00 local time (12:00 GMT), DHA news agency reports. The hostages were released shortly before midnight.
Officials say the suspect wanted to draw attention to the ongoing situation in Gaza.
A Palestinian flag was reportedly painted at the entrance of the building with a sign saying “doors will be open for Gaza”.
Police officers cordoned off access to the factory and medical staff were dispatched to the scene.
Officials say a large-scale investigation into the incident is under way.
Footage from the scene during the standoff showed relatives of some hostages clustered together at a police cordon some distance from the plant.
İsmet Zihni, whose wife works at the plant, told DHA she had sent him a message saying she had been taken hostage.
However, he added he did not know “if it was her or someone else”.
Relatives of the hostages had expressed frustration at the lack of information from Turkish officials or the police.
“We have been waiting for six hours without any official making a statement,” the father of one hostage told AFP earlier.
In a statement, P&G said it was relieved no-one was harmed during the incident.
“We are grateful to the authorities and first responders who managed the situation with courage and professionalism,” the company added.
It also said the suspect was not an employee.