An off-duty Hong Kong police officer was arrested along with seven other people on Friday as they tried to put pro-democracy posters on a footbridge, police said.
It's the first known case of a police officer being apprehended for supporting the massive demonstrations that have led to more than 6,500 arrests in the past seven months.
The officer, 31, and the seven other people aged 14 to 61, were arrested at 3:00 am on Friday in Tuen Mun, a district in northwest Hong Kong.
The individuals were accused of "possessing objects with intent to damage or destroy property", and suspected of attempting to damage a footbridge, according to a police statement.
Police said they found the group in possession of posters, plastic scrapers, gloves and electric drills, and that all eight were still in detention for further investigation as of Friday night.
Local media reported that the group was trying to build a "Lennon Wall" — collages of pro-democracy visual art which have sprung up on walls and roads across the city in the past few months.
"The police force attached great emphasis on its members' professional ethics," the police said in the statement, adding that any violation of the law must be handled "seriously and justly."
Among the thousands of protesters who have been arrested, 41 have been civil servants, including 24 from disciplines such as fire services.
No police officers have been arrested despite complaints of blinding some protesters, driving a motorcycle into a march and showing a reporter's ID card to a camera on live broadcast.
The city's chief executive, Carrie Lam, a pro-Beijing appointee, said on Thursday that she would not accept any accusation of police brutality and that the force had been smeared.
The protests, which were triggered by a proposal to allow extraditions to mainland China in early June, have morphed into a larger revolt against China's control over the semi-autonomous city.
Violent clashes between riot police and protesters often erupted during rallies and marches calling for democratic freedoms and independent inquiry into the havoc.