Turkey's four biggest unions will hold a one-day protest strike Thursday as anger over the country's worst mining accident mounts, with 282 workers confirmed dead and scores still trapped underground.
The unions said workers' lives were being put at risk to cut costs, and demanded that those responsible for the collapse of a coal mine in the western town of Soma in Manisa province be brought to account.
"Hundreds of our workers have been left to die from the very beginning by being forced to work in cruel production processes to achieve maximum profits," they said in a joint statement, calling on people to wear black.
"We call on the working class and friends of labourers to stand up for our brothers in Soma."
Anger at the disaster has swept across Turkey, where mining accidents are a frequent occurrence.
On Wednesday, thousands of protestors clashed with police in Ankara and Istanbul, accusing the government and mining industry of negligence.
The prosecutor's office in Soma has launched an investigation into the cause of the disaster, which has added to the pressure on Prime Minister Recep Tayyip Erdogan.
The premier has rejected claims of government culpability, saying that "such accidents happen".In an apparent attempt to downplay the disaster, he compared it disaster to other mining disasters elsewhere, saying that "204 people died in the UK in 1862 and 361 people in 1864".
- An electrical fault -
It is unclear how many workers are still trapped underground following the huge explosion at the mine on Tuesday, which was believed to have been set off by an electrical fault.
Mining operators put the figure at 90, but reports from rescue workers on the scene suggest the figure could be far higher. Most of the victims died of carbon monoxide poisoning.
Erdogan was forced to take refuge in a shop after a furious reaction from relatives of the victims and the missing, some of whom began kicking his vehicle.
An adviser of Erdogan was photographed kicking a protester in Soma, sparking outrage on social media.
Public anger also spilled onto the streets, where police used tear gas and water canon to disperse between 3,000 and 4,000 protesters in Ankara's downtown Kizilay Square, as well as thousands of demonstrators in Istanbul.
The disaster has added to the political pressure on Erdogan, who faced mass protests last summer and a huge corruption scandal involving his family and key allies in recent months.
"If the claims of negligence at the mine prove true, it will have a political price. Such a development would render corruption allegations targeting Erdogan's government more convincing," Professor Ilter Turan of Istanbul's Bilgi University told AFP.
Messages of condolence poured in from celebrities including superstar Rihanna, actress Eva Longoria and supermodel Adriana Lima.
Rihanna changed the background picture of her Twitter profile page in memory of the Turkish victims, while Lima wrote: "My thoughts are with you #turkey #soma".
- 'No more hope' -
Turkish Energy Minister Taner Yildiz said early on Thursday that the provisional toll had risen to 282 after more bodies were pulled out of the pit. No one has come out alive in the past 12 hours, he said.
Another 27 workers are being treated in hospital, and families of the miners who died in the disaster have begun to retrieve their bodies from a makeshift morgue a few kilometers from Soma.
Alahattin Mengucek, who came from Izmir to retrieve his son's body, said: "I'm waiting for my son. I've lost him in the mine, he just became a father eight months ago."
"What happened is just bad luck. The government is doing whatever it can to help us, but what can we do against fire and gas?" he added.
Raging fires have hampered rescue efforts, and emergency workers have still not been able to reach two underground shafts.
"We will try to save those who are still stuck one by one, but you know very well that there is no more hope. It's finished for them," said Murat Kurkoglu, a miner who joined the rescue effort.
Early reports said 787 workers were underground when the blast occurred. By late Wednesday, "close to 450" workers had been rescued, according to the mine operator, Soma Komur Inc.
But accounts from rescue workers cast doubt over these numbers.
Erdem Bakin, a doctor with the Search and Rescue organisation, said only around 70-80 people who were between the mine entrance and the transformer that exploded had survived.
"Those who were beyond were taken by the fire and they are all dead," he said.
- 'Tired of funerals' -
Explosions and cave-ins are common in Turkey, particularly in private mines, where safety regulations are often flouted.
Turkey's previous worst mining accident happened in 1992 when 263 workers were killed in a gas explosion in a mine in Zonguldak.
A lawmaker from the main opposition Republican People's Party (CHP) said it asked parliament last month to investigate work-related accidents at coal mines in Soma, but the government turned down the request.
"We receive tip-offs every day that workers' lives are under threat," local lawmaker Ozgur Ozel told Turkish media.
"We lawmakers from Manisa are tired of going to miner funerals."
Turkey's ministry of labour and social security said the mine had been inspected eight times in the last four years, most recently on March 17, and was found to comply with safety regulations.
Mining company Soma Komur said it had taken maximum measures to ensure safety.
Soma is a key centre for lignite coal mining and is located around 480 kilometres (300 miles) southwest of Istanbul.