Fresh clashes have erupted between police and protesters rallying against the Venezuelan government as a fifth person reportedly dies after being shot during earlier unrest.

Thousands of Venezuelans took to the streets in eastern Caracas amid a tropical downpour on Thursday to support a protest movement that appears to be gaining steam even as it turns more deadly.

Venezuela officials confirmed later in the day that a fifth person had died in the wave of anti-government protests now entering its third week.

The public prosecutor's office says it will investigate the death of Miguel Colmenares, 36.

He was shot at during a protest in the central city of Barquisimeto on Tuesday.

Nicolas Maduro, Venezuela's socialist president, is fighting off efforts to topple him as Venezuela struggles with shortages of food and medicine.

Dozens of people have been injured and more than 100 arrested over the past week in clashes in various cities, according to authorities.

Alfonso Marquina, an opposition politician, on Twitter identified the latest death as Antonio Gruseny Calderon and called him "another victim of the dictatorship".

Marquina and officials earlier said a 13-year-old boy was shot dead in protests on Tuesday in Barquisimeto.

Maduro supporters blamed

Marquina blamed that killing on so-called colectivos, armed supporters of the government whom the opposition accuses of attacking them during demonstrations.

A 36-year-old man was killed the same night in Barquisimeto, prosecutors said.

Two 19-year-old students were shot by police in earlier unrest, one on April 6 and one on April 11, according to authorities.

WATCH: Venezuela protesters mount pressure on President Maduro

Also on Thursday, Jose Manuel Olivares, another opposition legislator, said police fired tear gas "point-blank" at demonstrators in the state of Vargas.

"If they think they will scare us that way they are wrong. We will stay in the street!" he wrote on Twitter.

While demonstrations are often held in middle-class neighbourhoods, this most recent wave of unrest for the first time has prompted protests in the slums that have historically been bastions of support for the socialist revolution launched nearly two decades ago by Hugo Chavez, the late president.