CARACAS - Security forces and protesters fought around Venezuela on Thursday in streets blocked by burning barricades and a supporter of socialist President Nicolas Maduro was shot dead, the sixth fatality from more than a week of violence.

Maduro said a "fascist bullet" killed Alexis Martinez, a brother of a ruling Socialist Party legislator, in the central city of Barquisimeto. A local journalist said Martinez was shot in the chest while passing an opposition protest.

There have also been scores of injuries and arrests since the violence broke out eight days ago, the most serious unrest since Maduro was narrowly elected in April 2013.

The protesters, mostly students, want Maduro to resign, and blame his government for violent crime, high inflation, shortages of goods and alleged repression of opponents.

The most sustained clashes on Thursday were in the western Andean states of Tachira and Merida, which have been especially volatile since hardline opposition leaders called supporters onto the streets in early February.

In Tachira state capital San Cristobal, which some residents are describing as a "war zone," many businesses remained shut as students and police faced off again in barricaded streets.

With some residents saying they dared not leave their homes because of the violence, the government said it was taking "special measures" to restore order there.

"This is not a militarization," Interior Minister Miguel Rodriguez Torres said on state television from San Cristobal. "We are here to work for the great majority of people in Tachira. ... Before we have dialogue, we must have order."

Maduro says he will not let his rivals turn Tachira into "a Benghazi," referring to the violence-racked Libyan city.

On Wednesday night, Caracas saw one of the worst bouts of violence since the protests began nearly three weeks ago.

Around a square in the wealthier east of the city, security forces fired teargas and bullets, chasing youths who hurled Molotov cocktails and blocked roads with burning piles of trash.