CAIRO: A policeman died and tens people were injured when thousands of quarry workers and owners clashed with police in Egypt on Thursday, security sources and witnesses told Reuters.

The protesters marched into Al-Minya city, in the central province of Al-Minya 210 kilometers south of Cairo, and blocked a bridge spanning the Nile, to protest against a decision by the authorities to impose new duties on quarried rock, security sources said.

Police used teargas to disperse the crowd, but the protesters stoned police, injuring at least four officers, security sources said.

An official told the Associated Press that police fired tear gas Thursday at some 3,000 workers who were throwing stones.

One policeman died, and accounts differed as to whether he was killed during the stoning or from exposure to teargas.

Reports of the total number injured varied. Security sources said at least 17 riot police had been wounded, and more than 20 protesters were suffering the effects of teargas inhalation.

Police arrested some of the protesters. Estimates by security sources of how many ranged from five to close to 50.

The website of the independent daily Al-Masry Al-Youm said the government had imposed duties of LE 40 per ton of quarried stone, leading some quarries to shut down and lay off their laborers.

Protesters said they held the demonstration because petitions to officials had been ignored and some quarries had been shut for more than two weeks, the website said

However, an official told the Associated Press that the governor later reversed his decision to avoid more violence. He spoke on condition of anonymity because he was not authorized to talk to the media.

Labor unrest has become common in Egypt, usually over pay, and often in privatized companies. Even professional groups such as doctors, pharmacists and lawyers have stopped work or threatened strikes over pay. Worker frustration with rising prices and shortages of subsidized bread flared into two days of clashes with security forces in the city of Mahalla El-Kobra north of Cairo in April last year. Three people were killed and scores injured. –Agencies