Hong Kong Chief Executive Carrie Lam Cheng Yuet-ngor warned on Tuesday that escalating violence is pushing the special administrative region into an "abyss of destruction".

She appealed to the public to calm down, set aside differences on political issues and reject violence.

Meeting reporters ahead of the Executive Council, Lam appealed to the public, in a voice trembling with emotion, to pause and think.

"The top priority now is to oppose violence and safeguard the rule of law," she said. "Rational discussions will start after the city's law and order is restored. And that's when we can mend what has been torn apart."

Lam said developments over the past week validated her concerns that Hong Kong was in a dangerous situation. She reminded people that Hong Kong had been ripped apart by violent protests that started on June 9, which saw radicals clash with the police, and residential and business areas become virtual war zones.

Lam said the chief executive's responsibility is to ensure that Hong Kong remains a safe, orderly and law-abiding city.

Flights were canceled on Tuesday for a second consecutive day as protesters occupied large parts of the Hong Kong International Airport. All departing flights were canceled in the afternoon in the wake of what officials said was an unauthorized assembly seriously disrupting the airport's operations.

Also on Tuesday, Hong Kong's stock market dropped to its lowest level since Jan 4 at the end of trading.

Following the fall of all three major US indexes overnight, the benchmark Hang Seng Index fell by 1 percent as the market opened. The index continued on a downward trajectory, ending the day at 25,281.3, a decline of 543.42 points or 2.1 percent.

Shares of airline companies were among leading decliners in the wake of the cancellation of more than 300 inbound and outbound flights on Tuesday. Hong Kong's largest carrier, Cathay Pacific Airways, continued its drop on Monday. Shares of Cathay Pacific tumbled 2.96 percent to HK$9.51 ($1.21), a 10-year low.

At press time, police had not taken action against the illegal assembly at the airport.

Citing recent examples of the obstruction of law enforcement operations, the Hong Kong Police Force appealed to the public on Tuesday for cooperation in maintaining law and order.

At a daily news briefing, Chief Superintendent of Police Public Relations Tse Chun-chung said two months of violent protests against the now-shelved extradition amendment bill have created tensions between the public and police.

Daily police operations, even those unrelated to the protests, have been impeded to various degrees due to the hostility toward the police, Tse said.

He cited a recent incident in which police officers were blocked by over 50 residents as they investigated a suicide case in public housing in Tai Po on Sunday night. The officers were shut out of the building. Some residents targeted them with laser pointers while others surrounded a police van, according to the officer.