The State Council Hong Kong and Macao Affairs Office on Tuesday expressed its strongest condemnation over rioters who set fire to a man in Hong Kong, urging Hong Kong authorities to detain the suspect as soon as possible and punish him in accordance with law.

On Monday afternoon, a 57-year-old father of two daughters was set on fire when one of the rioters in a group he was admonishing for vandalizing a subway station poured flammable fluid over him and set him alight on a footbridge in Ma On Shan, New Territories.

The man got severe burns and is still in critical condition, according to the office.

"Such an act of burning in broad daylight was shocking and inhumane, and it seriously violated the bottom line of law, morality and civilization," Yang Guang, spokesman for the office, said on Tuesday. "We expressed great indignation and strong condemnation of the behavior, and also sincere sympathy to the victim and his family members."

"Heaven forbids the rioter's act," Yang said. "We must not let the violence continue to be rampant in Hong Kong."

"We firmly support the government of the Hong Kong Special Administrative Region, police and judicial authorities to take more powerful, bold and effective measures to punish violators, as well as stop violence, curb chaos, restore order and protect life and property safety of local residents to give a safe and peaceful environment back to the people."

Also on Tuesday, the HK Hospital Authority said the burned man is still under close inspection in the intensive care unit.

Police have classified the case as attempted murder, which carries a maximum sentence of imprisonment for life. The police asked any witnesses to come forward and provide information to the police.