MACAU: Riot police fired into the air in the southern Chinese territory of Macau as a May Day street protest turned violent Tuesday and officers scuffled with demonstrators in rare scenes of civil unrest.

Officers opened fire with what were thought to be starter pistols after the crowd of more than 1,000, protesting against labour shortages and conditions, broke through police cordons lining the march route.

Cheered by watching residents, they then began marching toward government offices.

Witnesses said they saw several protesters being dragged from the crowd by their hair by baton-wielding police while another man was seen staggering away clutching a wound to his face.

There were reports from some, however, that police had fired live rounds.

"I know what a starter pistol sounds like and they were not firing blanks," said lawmaker Jose Pereira Coutinho.

The protest started peacefully with demonstrators calling on the government to implement laws to reduce the number of illegal workers flooding into Macau to cash in on a recent casino-led economic boom.

But the mood turned when they reached a mortuary where the city's political leader Edmund Ho was mourning his father, who died recently.

They began chanting "Edmund Ho step down," and scuffles broke out as police tried to move the crowd along. - AFP/yy