The government of China's Hong Kong Special Administrative Region (HKSAR) strongly condemned the violence as "breaching the public peace and breaking the law deliberately" on Sunday.
"The police will take serious follow-up actions with those violent protesters," it stressed.
Despite police ban, protest ends with injuries
Around 3 p.m. local time on Saturday, protesters gathered in the Yuen Long district. They threw rocks and bottles, held iron poles, removed fences from the road, and built barricades out of street furniture and umbrellas.
Some threw rocks and bottles at police, attacked police vehicles and private cars and many refused to leave the area. To stop the violence, the police used what it called appropriate force, such as tear gas, sponges and rubber bullets.
The violence continued into the evening.
The HKSAR government said that it deeply regretted that some people still took part in the public procession and public meeting in Yuen Long, despite the prohibition and objection by the police.
"The economy of Hong Kong has been affected in a big way. Our exports in June saw a decrease of nine percent from last year and we are really concerned about this," said Chan King, vice president of Hong Kong Chinese Importers' and Exporters' Association.
"If the situation continues, the economy will be in big trouble."