The male reporter suffered a wound above his right eye and was treated by first aiders before being helped to an ambulance to be taken to hospital.
He had been covering the protest in the Sham Shui Po area throughout the afternoon, which included a government building getting vandalised and attempts to throw Molotov cocktails at the area’s police station.
The journalist said he wasn’t sure what struck him.
Earlier in the day, a female reporter from the station said a riot police officer had pointed a shotgun right at her at the intersection of Queensway and Queens Road East.
With journalists from other media outlets also getting splashed by a corrosive liquid while covering the clashes, RTHK’s English News And Current Affairs unit decided it was no longer safe for its reporters to be on the streets during the National Day protests.
Further reporting on the day’s events was being carried out from the station’s newsrooms.