Three people have died after a roof collapsed in the eastern town of Goma just before a visit by the Democratic Republic of Congo's president.
Prospective MP Pauline Wamariya told the BBC hundreds of people had gathered on top of a disused hangar.
The roof then gave way when people began to dance ahead of the arrival of President Joseph Kabila.
It is his first visit to Goma in the lawless east of the country since he took power in 2001.
The Democratic Republic of Congo is preparing for historic elections in July, and the official start of campaigning begins later this week.
On Tuesday, opposition parties criticised President Kabila for not keeping a pledge to meet them in the capital, Kinshasa and go campaigning in the east.
The elections are intended to end a post-war transitional period, with the government made up of various warring factions.
But armed men still roam parts of eastern DR Congo three years after the official end of the five-year conflict.