Another commentary by a Shenzhen University researcher, published by the China Daily, said the central government should deal with Hong Kong issues more decisively. The UN also denounced Tuesday's violence and called on the Hong Kong government to talk to its people.
Some protesters held signs apologising to passengers for the inconvenience caused by their demonstrations. Check-in counters reopened to queues of hundreds of tired travellers who had waited overnight for their flights.
The agreement stated that Hong Kong would "enjoy a high degree of autonomy, except in foreign and defence affairs" and be "vested with executive, legislative and independent judicial power".
Mr. Leung is among Hong Kong's lowest class.
Hong Kong's largest carrier, Cathay Pacific, has issued several statements condemning illegal protests in Hong Kong alight growing pressures from Chinese authorities over events compromising company's stakeholders.
"Hong Kong police have always facilitated peaceful and orderly protests over the years, but the extremely radical and violent acts have certainly crossed the line and are to be most severely condemned", he said.
"We ask for your understanding and forgiveness as young people in Hong Kong continue to fight for freedom and democracy". Only departing passengers will be allowed into the terminal to prevent protests from disrupting operations again.
Cathay also said it had fired two pilots, in an apparent response to their involvement in activity related to pro-democracy protests.
"One is now involved in legal proceedings".
One of them was arrested and charged for rioting in Sheung Wan on July 28.
On Tuesday evening, some violent protesters besieged and assaulted a traveler and a reporter at the Hong Kong International Airport, as well as obstructed an ambulance crew from taking the traveler to hospital, said a spokesperson for the HKSAR government.
Chinese state media has also posted messages of support for the Hong Kong police, describing what was happening in the city as "a shame".
Ms Lam defended the officers and has refused to engage in dialogue with protesters, saying they were threatening to push their home into an "abyss".
Earlier this week, the Chinese military stationed tanks in Shenzhen, presumably due to its easy access to Hong Kong-a thinly-veiled warning for protesters to comply or face the consequences.
"Their behavior shows extreme contempt for the law, seriously damages Hong Kong's worldwide image and deeply hurts the feelings of the broad masses of their mainland compatriots", the statement said.
On Monday China said the protests had reached a critical juncture, after a weekend of street clashes in which both police and protesters appeared to toughen their resolve. However, one individual, presumed to be an undercover Chinese official was injured.