Four people killed in one of three explosions during this year's Carnival celebrations in Bolivia died when a homemade bomb was deliberately detonated, police have confirmed.
Ammonium nitrate, dynamite and explosive oils were in the deadly device which exploded in Oruro on Tuesday evening, killing four and injuring a further 10, Police General Faustino Mendoza said Wednesday.
The bomb left a crater 1.3 meters wide and 43 centimeters deep. Trace fragments of dynamite and aluminum found by investigators suggest that more than 3kg of dynamite were used to detonate the device in a deliberate act of violence.
"We are sure that this is a criminal attack," said Oruro Governor Victor Hugo Vasquez.
In another incident, a street-food stand exploded along one of the Carnival routes, killing eight people and injuring 47. The explosion was apparently caused by a gas leak: oil had worn away the hose on the liquid gas tank.
The owner of the stand was a 71-year-old woman who, together with her children and grandchildren, was among those killed.
Authorities are continuing their investigations and say they believe the two incidents may even be related. "We do not rule out the possibility that the two explosions are coordinated events," said Defense Minister Javier Zabaleta.
Carnival weekend closed with a death toll of 42, plus more than 120 injuries, Federal Minister Carlos Romero told the Cronica. Last year's Carnival festivities killed 54. In 2016, 52 people died.
Following Tuesday's incident, President Evo Morales called for an exhaustive investigation and said Bolivia stands in solidarity with the families of the victims.
"Very saddened and concerned because we have a tragedy again, and the death of innocent bystanders in Oruro has our country in mourning after another explosion," he wrote on Twitter.