“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,” President Evo Morales said on Twitter.
Governor Victor Hugo Vásquez confirmed the two fatalities in the northwestern city known for its cobblestoned streets and colourful carnival celebrations. Local media said between four and six others were hurt the blast.
On Saturday, another tank exploded in the same area and killed eight people and injured another 41.
In Oruro, about 25,000 dancers take part in the city-wide event that is Bolivia’s biggest tourist attraction, bringing as many as half a million tourists to Oruro.
The pageant along the city’s cobblestones is a mixture of Spanish colonial traditions with those of the ancient indigenous Inca and Aymara peoples in a ritual seeking better farming and good health.
In 2001, UNESCO declared Oruro’s city carnival an intangible cultural heritage of humanity.