Police in Turkey free hostages taken by 'pro-Gaza gunman' at US factory near Istanbul

Images of the assailant shared online showed a man holding a gun, with what appeared to be a suicide vest strapped to his chest

Police cordon off the area outside the Procter & Gamble factory near Gebze, north-west Turkey, on February 1. Dia / AP

Live updates: Follow the latest news on Israel-Gaza

Seven workers taken hostage by a pro-Palestinian gunman at a plant near Istanbul owned by US consumer goods giant Procter & Gamble were released by Turkish police on Thursday evening.

The police raid took place almost nine hours into the standoff when the lone gunman went to the bathroom, local officials said.

The man, who was staging a protest against the war in Gaza, was detained unharmed, local Governor Seddar Yavuz told reporters.

"The man's aim was to stop Israel's massacre in Gaza and to open the Rafah gate in Egypt" for the delivery of humanitarian aid for trapped civilians, Mr Yavuz said.

"When he went out for a bathroom break, our security forces carried out an operation without harming the hostages."

Photos and videos of the assailant shared earlier online by one of the hostages and verified by AFP showed a man, with his face hidden by a Palestinian scarf, holding a gun.

He had what appeared to be a suicide vest strapped to his chest.

The man was standing next to a drawing of the Palestinian flag and the words "The door will be opened for Gaza" painted on the wall in red.

Haberturk TV earlier said police had established contact with the captor and were trying to negotiate the hostages' release.

"Earlier today, we evacuated our Gebze facility and are working with local authorities to resolve an urgent security situation," P&G said in a statement released to AFP.

100 days of Israel Gaza war - in pictures

Relatives of the hostages questioned why the assailant would aim for workers in Turkey, which is strongly supportive of the Palestinian cause, to show his solidarity with the people of Gaza.

"He supposedly does this for Islam but they are the ones who harm Islam the most," Sedat Degirmenci, whose son-in-law was taken hostage, told AFP.

Cigdem Aydemir, the mother of a 26-year-old woman taken hostage at the plant, said: "If you do this for Palestine, go and fight there."

Like other relatives, Ms Aydemir was following the hostage-taker's Instagram account for updates on the situation.

The account became inaccessible by Thursday evening.

"What does my daughter have to do with this?" said Ms Aydemir. "I can only pray."

Turkish President Recep Tayyip Erdogan has emerged as one of the Muslim world's harshest critics of Israel because of the civilian death toll from its campaign against Hamas militants.

He has called Israel a "terrorist state" and compared Israeli Prime Minister Benjamin Netanyahu to Adolf Hitler.

Mr Erdogan has also accused the US of supporting "genocide" in Gaza.

His comments reflect anger across the mainly Muslim – but officially secular – country at the US for its support for Israel.

Hundreds of protesters stormed a south-eastern Turkish air base used by US and British forces on the eve of US Secretary of State Antony Blinken's visit to Ankara in November.

Turkish online campaigns are also trying to organise boycotts of US products such as Coca-Cola and Starbucks.