More than 140 people were injured at a political rally in the central square of Armenia's capital on Friday when clusters of balloons exploded, according to the Associated Press.
According to emergency officials, 104 people had to be hospitalized for burns after the explosion in Yerevan.
The explosion was caused by a smoker who lit a cigarette near the balloons, said the AP.
The crowds had gathered for a government campaign event ahead of parliamentary polls, according to the BBC.
Health ministry spokesperson Shushan Hananyan said that some of the injured were hurt during the chaos that ensued after the blasts.
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"I heard an explosion and saw flames rising high," a 30-year-old woman told Reuters. "People rushed away from the square, and I saw a man with a burnt face and a girl whose back was on fire."
The BBC said that despite the incident, President Serge Sarkisian did address the rally.
The Republican Party and its ally Prosperous Armenia are likely to win 60 percent of the votes in Sunday's election, according to opinion polls cited by Reuters.
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Here is footage of the incident from Panorama.am: