Hundreds of people in Hong Kong have marched to protest against Cathay Pacific's dismissal of employees who took part in previous protests.
Hundreds of protesters have taken to the streets of Hong Kong to denounce Cathay Pacific Airways for dismissing crew taking part in or supporting anti-government rallies that have swept the Chinese-ruled city for weeks.
The Hong Kong Confederation of Trade Unions (HKCTU) switched the protest venue, originally planned to be outside the airline's airport headquarters, Cathay City, to the central financial district after police refused permission.
The airport was forced to close two weeks ago after protesters thronged the arrivals hall for days, grounding about 1,000 flights and occasionally clashing with police.
Cathay was targeted for its sacking of 20 pilots and cabin crew and what staff have described as "white terror", a phrase used in Hong Kong and elsewhere to describe anonymous acts that create a climate of fear.
"Revoke termination, stop terrorising CX staff," proclaimed a black banner in English at the protest site where at least 2,000 gathered. "Uphold our freedom of speech."
CX is the airline code for Cathay.
The airline has been caught in the crosswinds between authorities in Beijing and protesters who have staged sometimes violent demonstrations since June that have grown into the biggest challenge for authorities in the former British colony since it returned to Chinese rule in 1997.
China has denounced the protests and accused the United States and Britain of interfering in its affairs in Hong Kong.
It has sent a clear warning that forceful intervention is possible.
Rebecca Sy, former head of a flight attendants' association, said she was fired without explanation after managers saw her Facebook account.
"We never faced any disciplinary action from the company before. How come now they just terminate me without any valid reason? By simply showing me those printouts of my own private Facebook account?"
China's aviation regulator demanded Cathay suspend staff from flying over its airspace if they were involved in, or supported, the demonstrations.
At least 20 pilots and cabin crew have since been fired, the HKCTU said.
"Earlier this month, the Civil Aviation Administration of China issued a directive with regards to new safety and security measures with which we are required to fully comply," Cathay's director for corporate affairs, James Tong, said in a statement.
"We fully support the upholding of the Basic Law and all the rights and freedoms afforded by it. At the same time, we are also required to adhere to all of our regulatory duties, including those prescribed by the authorities in mainland China. The airline must do this; there is no ground for compromise."
The Basic Law is the mini-constitution under which Hong Kong is ruled.
The protests in the Asian financial hub have posed the biggest challenge for Communist Party rulers in Beijing since President Xi Jinping took power in 2012.
Unrest escalated in mid-June over a now-suspended extradition bill that would have allowed people to be sent to mainland China for trial in Communist Party-controlled courts.