Five teenagers were arrested on Friday over clashes between anti-government protesters and residents in Hong Kong that claimed the life of a 70-year-old man after he was struck by a brick.

A girl aged 15 and her boyfriend were among those arrested in relation to a fight that broke out between two groups in Lung Wan Street, Sheung Shui, on November 13.

Police did not reveal the nature of the offences the group aged 15-18 were suspected of committing.

Chaos erupted during a heated argument outside North District Town Hall between about 20 black-clad protesters and residents of the Hong Kong border town, who had been clearing bricks left on the street earlier by activists.



Online video footage showed the two sides had been throwing bricks at each other when Luo Changqing, who was taking pictures at the scene, was hit on the head and fell to the ground.

The contract cleaner for the government was certified dead in hospital at 10.51pm the next day, on November 14.

Liam Lam Tsz-king, a North District councillor-elect, said the family of a 16-year-old boy approached her on Friday after his arrest and she helped them find a lawyer.

The family was told by police the boy was captured on CCTV footage picking up a brick. The boy’s 15-year-old girlfriend was among the arrested.

The incident on November 13 lasted about one minute before the black-clad gang opened umbrellas to shield themselves and began their retreat.

Police searched the area, but no arrests were made at the scene.

Those arrested on Friday were detained at the New Territories North Regional Headquarters in Tai Po. No further details were available, as of late on Friday.

Police offered an HK$800,000 (US$102,000) reward for information on the 70-year-old’s killer earlier this week. The bounty is the largest posted on the force's website.

After the elderly man’s death, the central government's liaison office in Hong Kong expressed its “deep condolences” and urged Hongkongers to “denounce violence and protect the rule of law and stability of society together”.