HONG KONG (AP) — A Hong Kong university student who fell off a parking garage after police fired tear gas during clashes with anti-government protesters died Friday, in a rare fatality after five months of unrest that is bound to intensify anger in the semi-autonomous Chinese territory.

The Hospital Authority said the 22-year-old died Friday morning, but didn't provide further details.

Hundreds of angry masked protesters marched through the busy central district at lunchtime, chanting "Disband the police force," ''Hong Kong people, revenge" and "A blood debt must be paid in blood." Some carried white flowers and placards that read "Hong Kong is a police state."

Protesters demanded justice for Chow Tsz-Lok and hurled abuse at several police officials on site, calling them "murderers."

"His death is a reminder to us that we cannot give up," one protester said on local television.

Although the cause of his fall has not been determined, it deepened anger against police, who have been accused of heavy-handed tactics since protests demanding democratic reforms started in June.

Local media reported that Chow has been in a coma with brain injury since he was found early Monday sprawled in a pool of blood on the second floor of the building. Police believed he plunged from an upper floor but it wasn't captured by security cameras.

Minutes earlier, television footage showed riot police firing tear gas at the building after objects were hurled down at the officers in the street when they chased off a mob. Police didn't rule out the possibility he was fleeing from tear gas but noted officials fired from a distance. Police also denied claims that officials pushed the victim down and had delayed emergency services.

The government expressed "great sorrow and regret" over Chow's death despite undergoing surgery and treatment.

"The police has stated earlier that they attach great importance to the incident and the crime unit is now conducting a comprehensive investigation with a view to finding out what happened," it said in a statement.

There have been only few fatalities amid the unrest, with previous reports of deaths by suicide and a man who fell to his death while hanging pro-democracy banners on a building.

At the University of Science and Technology, Chow's schoolmates staged rallies this week and on Thursday disrupted a graduation ceremony. The university president dabbed away tears as he announced Chow's "tragic" death Friday on the second day of the convocation, with the audience standing to observe a moment of silence.

Calls emerged online for memorial events Friday to mourn Chow in multiple locations including at the garage in the suburb where he fell.

The protests were sparked by a now-shelved extradition bill to mainland China that many sees as Beijing's creeping interference on legal and other rights guaranteed to Hong Kong when the former British colony returned under Chinese rule in 1997.

The movement has since expanded to include other demands, including direct elections for the city's leaders and an independent investigation into alleged police brutality.