Anti-government protests were planned in different locations in the Asian financial hub, including one at the city's international airport for a third day.
The broadside poses a major commercial challenge to Cathay, which already reported tumbling bookings last week as a result of the anti-government protests gripping Hong Kong.
Increasingly violent protests have plunged Hong Kong into its most serious political crisis for decades, posing a serious challenge to the central government in Beijing.
US President Donald Trump has condemned hatred and white supremacy in a public address following the mass shootings in Texas and Ohio late on Saturday.
A total of 46 countries including US and China signed the Singapore Convention on Mediation Wednesday, also called the United Nations (UN) Convention on International Settlement Agreements Resulting from Mediation
The annual ceremony was held at the Peace Memorial Park near Ground Zero which was attended by representatives from about 90 countries including the US, Russia and Britain.