A man died in Hong Kong after being hit in the head during clashes between protesters against democracy and supporters of the government.
Officials say the man was on a lunch break from his job as a cleaner when he was hit in the head by "solid objects thrown by masked riots".
The incident occurred less than a week after a student died after falling from a building during a police operation.
Hong Kong was beset by political unrest for more than five months.
In a statement Thursday, the Hong Kong government said it was "saddened" by the death of a man who was described as a contracted worker by the Food and Environmental Hygiene Division (FEHD).
Video is said to be from the incident showing protesters and government supporters throwing bricks at one another before a person falls to the ground after being hit in the head.
FEHD said the collision took place on Wednesday and the man, who is reportedly 70 years old, died in hospital the next day.
Police said they were investigating the incident.
Last Friday, 22-year-old student protestor Alex Chou died after falling from a parking ledge during a police operation to clear the area. He was reportedly trying to get out of tear gas.
This week in Hong Kong there is an escalation of violence with intense street battles, violent clashes at universities and protests at noon.
On Monday, a police officer shot an activist in the torso with a live bullet and a pro-government supporter was set ablaze by protesters.
Why are there protests in Hong Kong?
Hong Kong is part of China, but as a former British colony it has some autonomy and people have more rights.
Protests began in June against plans to allow extradition in the mainland ̵
The bill was withdrawn in September, but demonstrations have continued and full democracy is now required and investigation of police conduct.
Clashes between police and activists became more violent and in October the city banned all face masks.