A protester uses his hand to prevent the doors of a Mass Transit Railway (MTR) subway train from closing during a disruption of MTR services at Fortress Hill station in Hong Kong, China August 5, 2019. Hong Kong was bracing for major disruptions to business on Monday as a general strike threatens to paralyse parts of the Asian financial centre, with more than 100 flights already cancelled, amid a broader anti-government campaign. REUTERS/Kim Kyung-Hoon

Mass Transit Railway (MTR) subway personnel try to prevent a protester from blocking the door of a train as protesters disrupt MTR services at Fortress Hill station in Hong Kong, China August 5, 2019. The strike comes after another weekend of violent protests, which the government said were pushing the city to "an extremely dangerous edge". REUTERS/Kim Kyung-Hoon

Protesters stand at a door of a Mass Transit Railway (MTR) subway train to disrupt its service at Fortress Hill station in Hong Kong, China August 5, 2019. Police said on Monday they arrested 44 people after sometimes violent clashes overnight when police fired tear gas to disperse demonstrators who moved swiftly across the city in flash mob-style actions. REUTERS/Kim Kyung-Hoon

A commuter argues with a protester as a train is stalled during disruption of the Mass Transit Railway (MTR) services by protesters, in Hong Kong, China August 5, 2019. The Chinese-controlled city has been rocked by months of protests that began against an extradition bill that would have allowed people to be sent to mainland China for trial and have since evolved into calls for greater democracy. REUTERS/Kim Kyung-Hoon

Passengers shout at protesters for disrupting Mass Transit Railway (MTR) subway train services at Fortress Hill station in Hong Kong, China August 5, 2019. The protests have at times shut government offices, blocked roads and disrupted business, posing the greatest political challenge to the former British colony since it returned to Chinese rule in 1997. Millions of people have taken to the streets to vent anger and frustration at the city's government, presenting the biggest popular challenge to Chinese leader Xi Jinping since he came to power in 2012. REUTERS/Kim Kyung-Hoon

Passengers wait for the resumption of Mass Transit Railway (MTR) services during a disruption by protesters at Fortress Hill station in Hong Kong, China August 5, 2019. Rail operator MTR Corp announced the suspension of services between the bustling shopping district of Causeway Bay and Quarry Bay on Hong Kong island. Services from Kowloon Tong to stations close to the border with mainland China were also disrupted, Hong Kong media reported. REUTERS/Kim Kyung-Hoon