At least three protesters have been shot dead by police this morning at the Canadia industrial complex in the capital’s Por Sen Chey district, Phnom Penh deputy police chief Chuon Narin has confirmed.

The use of force came as riot police moved in to break up a demonstration by thousands of workers who blocked Veng Sreng street, the site of an ongoing demonstration that began yesterday evening and saw hundreds of riot police deployed to the area after midnight.

Only moments ago, Post reporters on the scene confirmed that the widespread use of automatic weapons fire was still ongoing.

Union leaders and rights activists reported even higher death totals.

Rong Chhun, president of the Cambodian Confederation of Unions, said he had received information that four strikers had been shot dead and many more injured.

“The situation now is still tense,” he told the Post. “Why are they cracking down on us as we just demanding our salary?”

Chan Soveth, a monitor for local rights group Adhoc who was at the scene, also said he had heard four strikers were killed, with another 10 badly injured and multiple arrests.

“They were beating people on their heads,” Soveth added, saying authorities tried to chase strikers who attempted to run to their rented rooms near the site.

National Military Police spokesman Brigadier General Kheng Tito, who would confirm only one death when reached earlier, defended the use of force.

“We’re just doing our jobs. We fear the security situation, so we have to crack down on them,” he said. “If we allow them to continue the strike, later on, it will become messy and more complicated to control.”

Tito added that nine police officials were injured by stones, some fired from slingshots, during clashes with workers in the area.

Dave Welsh, from labour rights group Solidarity Center, condemned the police use of live ammunition as outrageous.

“In that economic zone, things have been getting out of hand,” he said. “Whatever the case, this is complete disproportionate use of force, illegal and completely outrageous on behalf of the government."

The demonstration comes amid an ongoing national strike that began last week when the Ministry of Labour's Labour Advisory Committee set a new monthly minimum wage of $95 - $65 less than striking unions demanded. The ministry raised the minimum wage another $5 earlier this week. Additional reporting by Shane Worrell and Sean Teehan