They say Argenis Hernandez was shot in the stomach on Friday in the city of Valencia and later died in hospital.
Also on Friday, bus driver Wilfredo Rey died after being shot by a group of hooded gunmen in San Cristobal.
At least 33 people have now been killed during weeks of protests over the high inflation and basic good shortages.
Meanwhile, supporters and opponents of the president staged rival rallies in the capital Caracas on Saturday.
This comes a day after riot police in the city  clashed with anti-government demonstrators who were protesting against the arrest of two opposition mayors.
The mayors were detained over their alleged role in the unrest.
The opposition says the government is violently repressing the protests and trying to silence the administration's critics.
President Maduro has blamed the violence on "fascist groups", accusing them of planning a coup against his government.
He says he has repeatedly invited them to the presidential palace for talks, but that they have refused to attend.
Opposition leader Henrique Capriles said he accepted the invitation but is yet to meet Mr Maduro.

Peter Ward, 54 of Barnstaple in Devon and Richard Hiley, 30 of Tividale in the West Midlands were sentenced at Birmingham Crown Court on Monday.
Ward was given five years and two months, Hiley five years.
The pair pleaded guilty to possession, supply and importation of Class A and Class B drugs.
Peter Ward was known online as PlutoPete. His business specialised in supplying military-grade foil packaging that claimed to hide illegal materials from detection.
He also provided new psychoactive substances, commonly known as legal highs.
He was arrested by National Crime Agency officers in Barnstaple in October 2013 following an international operation targeting prominent vendors on dark web marketplaces like Silk Road.
Officers searched Ward's rural home and found class A and B drugs and numerous computers.
Analysis uncovered his close working with an ex-customer, Richard Hiley, who was commissioned by Ward to convert bitcoins into cash.
In December 2013, NCA officers raided Hiley's address in the West Midlands after financial records seized from Ward identified large scale transactions between the pair.
Hiley also pleaded guilty to two counts of importing a prohibited weapon after he imported five stun guns. He said they were for personal protection.
NCA Branch Commander, Ian Glover, said: "Criminals and their customers like to think that dark web market places provide an anonymous haven.
"The reality is that law enforcement works together internationally to identify and pursue these people."
Source: US Department of Justice

The report focuses on the impact of sea level rises on the Dawlish to Teignmouth line which connects Cornwall and Devon to the rest of the UK.
The line was closed for two months in 2014 after it was destroyed by storms.
Network Rail said the study would be "key" to long-term developments.
The report, published in the Journal of Transport Geography, said that 10% of journeys on the line, which was rebuilt and reopened in April 2014, could be affected by 2040.
The report said adverse weather disrupted the line about 10 days per year, but according to sea-level predictions that could rise to almost 40 by 2040 and up to 120 by 2100.
Academics from Plymouth University, the University of Leeds and the University of York identified a link between sea-level change and rail incidents over the last 150 years.
The academics said there could be similar implications for other vulnerable stretches of railway throughout Wales, south-east England, the Cumbrian coast and Scotland.
Dr David Dawson, from the University of Leeds, said the long-term future of the line was "really worrying".
The report predicts diverting routes could potentially cost billions of pounds.
Network Rail said it hoped to develop "long-term interventions" to "secure the future" of the line.
The Department for Transport said it had invested Â£31m into improving the resilience of the route and was "exploring the potential for longer-term improvements in the area".
In January, the prime minister backed a new Okehampton railway route as the "most resilient" alternative to the vulnerable Dawlish line.
Two people have died from gunshot wounds during protests against President Nicolas Maduro's government, eyewitnesses and local media say.
[NEXT_CONCEPT]
A major vendor on the illegal Silk Road website and his business partner, were sentenced to five years in prison for drugs offences.
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Climate change could disrupt up to a third of rail services travelling to and from the South West within the next 100 years, a study suggests.