A 14-year old Venezuelan schoolboy has died after being shot in the head during an anti-government protest in the country’s restive western region.

Preliminary investigations suggest the boy, named variously as Kluiverth or Kluiver Roa, was injured during a confrontation between police and protesters in the city, and died on the way to the hospital, according to the San Cristóbal Human Rights Commission president, José Vicente García.

A photo of the middle school student lying in a pool of blood, his backpack hanging over his shoulder, as a man frantically tries to staunch the bleeding was widely shared on social media around the South American country on Tuesday afternoon.

The head of citizen security for the state told reporters that circumstances of the boy’s death were still unclear. “At one point these hooded protesters intercepted four police officers, snatched their motorbikes and to get rid of the protesters, one of the officials shot at the ground,” Colonel Ramón Cabezas told reporters.

“When the protesters scattered … we saw the students lifting the body

of this youngster from beneath a car, we don’t know for now how he got

there.”

Other stone-throwing students were injured during the clashes, said Reinaldo Manrique, a student leader.

One of the country’s more radical opposition parties country immediately called for a protest in the capital on Thursday to demand an investigation into the cases of students who have died at the hands of the government.

“There are no words to transmit my pain and indignation,” said hardline opposition leader María Corina Machado on Twitter. “They’ve killed a 14-year-old child. A kid who was protesting with his classmates.”

Residents of the university town, which has become a hotbed of anti-government protests, were outraged.

“How are you going shoot point-blank at a student who’s just leaving school to go home?” asked Glenda Lugo. “We’re tired of this injustice.”

Ruling party officials swiftly condemned the killing and offered condolences to the family.

The Venezuelan ombudsman, Tarek William Saab, a federal official charged with defending human rights, said on Twitter that he deplored the “vile murder” of the teen, who he named as Kluiverth Roa, though other officials spelled his first name differently.

Police use teargas as they clash with opposition students during a march against President Nicolás Maduro’s government in San Cristóbal. Photograph: Stringer/Venezuela/Reuters

Saab said officials had already detained the police officers supposedly involved in the killing.

The interior minister, Carmen Meléndez, pledged that the government would pursue Roa’s killer “relentlessly”, while also calling for calm.

It is not clear who fired the shot, which García said there was reason to believe came from a shotgun. The attorney general’s office has opened an investigation into the teenager’s death.

Last month, the government issued a policy change to allow law enforcement officials to open fire and use deadly force to control protests. At the time, human rights groups said the new regulations were dangerously vague, but Saab defended them.

Tensions are running high in Venezuela following of a slew of bad economic news and the arrest last week of the opposition mayor of Caracas. February marks the first anniversary of massive street protests that choked neighbourhoods around Venezuela and left more than 40 people dead. San Cristóbal was seen as the epicentre of last year’s protests.

Dissatisfaction with the administration has grown in the past year, but opposition leaders have so far been reluctant to call for similarly large-scale protests.