Venezuelan forces clash with anti-Chavez protesters

CARACAS (Reuters) - Venezuelan security forces clashed with protesters on Thursday, using tear gas, rubber bullets and water cannons to break up a march against President Hugo Chavez's plan to scrap term limits.

Thousands of students marched through the capital to the electoral authority's headquarters to protest what they say is Chavez's authoritarian proposal to use a referendum in December to amass power and fulfill his vow to rule for decades.

For hours, demonstrators set trees ablaze and threw stones, bottles and metal barriers at security forces in running battles across downtown Caracas. Some protesters were injured but there were no reports that any were in serious condition.

It was the worst violence at a protest since students demonstrated against Chavez's closing of the last nationwide opposition television network in May, Reuters witnesses said.

Congress, which has no opposition members, plans to pass a raft of constitutional changes on Friday, including empowering police to detain people without charges when Chavez declares there is a political crisis.

Venezuelans must approve the changes in a December referendum.

Chavez is popular among the majority poor because of his spending of oil income on schools, clinics and food subsidies.

That popularity and sweeteners in his proposed legislative package, such as shortening the work day, should secure him an easy win in the vote, pollsters say.

But with the opposition, the Roman Catholic Church and rights groups also criticizing the changes, turnout for the referendum could be low, they say.