(Reuters) - Around 4,000 striking workers on Monday forced their way into a factory in Cambodia that makes clothing for U.S. sportswear company Nike and clashed briefly with colleagues who had remained on the job before being dispersed by police.

Police said at least 11 policemen and eight workers were injured.

The confrontation at the Sabrina factory followed a series of deadly incidents at factories in Bangladesh, the world's biggest clothing exporter after China, including the collapse of a building in April that killed more than 1,000 people.

Witnesses said many of the workers pressing for a wage increase at the Sabrina plant west of Phnom Penh were armed with sticks and rocks and smashed windows before being confronted by non-strikers.

About 1,000 police and soldiers used batons and shields to separate the sides and disperse the strikers.

"We had to break them up in order to protect the whole factory from destruction," Kheng Tito, a national military police spokesman, told Reuters.

Sao Sreytouch, a striking worker, said she was confronted by other workers with sticks and steel pipes upon entering the factory, where workers walked out on May 21.

Sun Vanny, president of the Free Trade Union (FTU) at Sabrina, accused police and factory owners of colluding "to cause chaos" and force an end to the strike.

Hong Luy, chief of administration for Sabrina (Cambodia) Garment Manufacturing said last week that the company could not afford to raise workers' pay, which stood at the equivalent of up to $102 a month.

A spokeswoman for Nike told Reuters last week that compensation at the Cambodian factory was the responsibility of the factory, but that Nike was in "close contact" with the factory and would "continue to monitor the situation".

"It is our understanding that this factory raised its own minimum wage on May 1 and pays above the country's minimum wage," Nike spokeswoman Mary Remuzzi told Reuters by e-mail last week.

The sportswear giant has five factories in Cambodia, representing just 0.6 percent of its global total.

The deadly incidents in Bangladesh and other mishaps, including a collapse at a factory in central Cambodia that killed two people, have generated renewed global interest in safety standards.

Many Western brands, attracted by cheap labour, have turned to Asia to have garments made at a cost that will make them attractive to bargain hunters in Europe and North America.

(Reporting by Prak Chan Thul; Writing by Amy Sawitta Lefevre; Editing by Ron Popeski)