People from all walks of life in Hong Kong formed a united front on Friday to speak out against violence after the city has endured radicalism and unrest since mid-June as a result of repeated protests.

Business tycoons like Li Ka-shing and entertainers including Charmaine Sheh expressed their concerns over the escalating violence and called for the restoration of the rule of law.

Their appeals came amid worries of more possible clashes over the weekend between radicals and the police and a call for students to boycott classes as the new school year begins in about two weeks.

Hong Kong has seen protesters blocking roads, setting fires and besieging government buildings and police stations more than 70 times in 18 days since June 9, Central District Commander Tse Ming-yeung said on Friday. Protests have also seriously affected the normal operation of Hong Kong International Airport, one of the world's busiest traffic hubs.

After the city's economy and people's livelihoods started to feel the pinch from the monthslong turmoil, Hong Kong billionaire Li Ka-shing took out advertisements in several local newspapers on Friday urging an end to violence. Earlier, another tycoon, Peter Woo Kwong-ching, also spoke out against the unrest.

Hong Kong's pop stars and celebrities on Friday also called for the return to law and order in the city. Actress Sheh, actor Shawn Yue Man-lok and singer Yeung Chin-Wah all stressed that Hong Kong is an inalienable part of China.

The Motion Picture Industry Association in Hong Kong said in a statement that the people of Hong Kong have a right to pursue their political agendas, but they can't cross the bottom line of humanity and morality. Nor should they endanger others and destabilize society, or harm national sovereignty.

"If such antagonism and rifts continue, Hong Kong will lose its glory and be beyond redemption," the statement continued.

Multinational firms in Hong Kong and chambers of commerce have also warned against the impact of escalating violence and disruptions to Hong Kong's economy, residents' livelihoods as well as the city's image abroad.

Peter Wong, deputy chairman and chief executive of the Hongkong and Shanghai Banking Corporation, said that as a global financial center, Hong Kong has a solid foundation and its hard-won position and reputation should be cherished by its residents.

Though people expressing their opinions peacefully should be respected, "violent incidents have been going on one after another and the situation is getting worse, affecting local people's livelihood and endangering public safety", Wong said.