A float crashed during Rio de Janeiro's world famous Carnival parade Sunday evening and injured at least 20 people, including three people reported in serious condition, but organizers proceeded with the show.

The incident involved the last float of the first samba school parading through Rio's Sambadrome. The float of samba school Paraiso de Tuiuti crashed into a fence that separates the stands from the pavement, injuring spectators, revelers and journalists. One reporter had an exposed fracture.

Police began an investigation as soon as the float finished its transit through the Sambadrome. Police investigator William Lourenco Bezerra said the three conductors of the float would be questioned Monday morning, adding that one driver already had been identified as the main focus of the probe.

"The last float went into reverse and ended up pressing revelers against the fence on one side. That caused chaos. Then the conductors made a quick maneuver to the opposite direction and injured more people," Bezerra said. "The main conductor of the float mixed with the rest of the samba school and left. But he has already been identified and will be investigated."

Rio's state health secretary said in a statement that eight of the 20 people involved in the incident are in hospital and three women were in serious condition.

The pavement of the Sambadrome was wet because of a persistent drizzle. Rain can make the big floats harder to guide.

The drizzle also created more difficulties for firefighters to cut a fence to remove two women drenched in blood.

In a statement, samba school Paraiso do Tuiuti said it "deeply regrets" the incident. "Our board offers its deepest sentiments and is open to make any clarifications as soon as all the causes of the accident are investigated. We will offer all the assistance to the victims of this irreparable incident," the samba school said.

Despite the accident, the head of the Rio parade, Elmo dos Santos, said that "the show must go on."

"The rain made the car veer to the left. Organizers tried to adjust, but then they lost control. It is all regrettable, but we cannot stop," dos Santos told journalists.

Elmano Santos, a reveler from Rio, said the float missed him by inches (centimeters).

"It was very quick. I saw a few journalists taking pictures close to the float get injured. I can't remember the last time I saw an accident here," he told the AP.

Paraiso do Tuiuti was the first of six samba schools parading in the night's extravaganza at the Sambadrome, which was scheduled to run until early Monday.

Only revelers at the entrance of the Sambadrome were aware of the incident. Many who found out later agreed with the decision to carry on.

"It is all very sad, but to stop Carnival would create an even bigger problem," said Jonas Elias, a tourist from Salvador. "Of course this spoils the party a bit, but to frustrate all this crowd would make the tragedy even bigger."

