Hong Kong protesters shot bows and hurled petrol bombs from a barricaded university campus on Sunday.
The Hong Kong Polytechnic University campus was one of five universities that protesters used to block the city's central cross-harbour road tunnel.
According to reports, a policeman and a media officer were wounded in the incident.
Clashes also broke out on the artery of Nathan Road of Mong Kok, a frequent venue for unrest.
Meanwhile, China's People's Liberation Army (PLA) soldiers were seen monitoring developments from a base close to the university.
It comes after a government spokesman clarified that the military had initiated the operation as a "voluntary community activity" and not at the request of the government.
Earlier, the soldiers were seen helping residents clear debris that blocked key roads.


US and Iran signal a peace deal is close
Qatar rejects media report on energy production decisions
Trump says Iran war deal close as Strait of Hormuz tensions linger
Victims' families mark Air India crash anniversary with prayers and tributes
Ebola outbreak spreads to crowded displacement camp in Congo
Fire breaks out at New Zealand's Wellington airport, disrupting flights
Ukraine and Russia trade overnight drone strikes, officials say
UN says Taliban arrest 30 women for violating hijab rules in Afghanistan
