Riot police have fired tear gas to disperse hundreds of demonstrators in southern China on the fourth day of protests against the planned expansion of a coal-fired power plant.

China's official Xinhua news agency said around 500 people gathered on a highway Friday in the town of Haimen in Guangdong province when police fired gas cannisters towards the crowd.

Large scale protests and clashes between police and demonstrators began on Tuesday.

In response to the protests, the local government said that it would temporarily suspend the power plant project. But demonstrators say they have not heard directly from authorities on the matter. They are demanding the release of several protesters detained this week.

Protests in China over corruption, pollution, wages and land seizures have become more common in recent years, in part, analysts say, because of the spiraling growth of the Internet. China currently ranks first in Internet use, with more than 450 million Internet users.