A bull attacked several people after the collapse on Sunday at the Gilberto Charry Bullring in the municipality of Espinal, Xinhua news agency quoted the authorities as saying.
A number of children were reported missing in the chaos following the event.
Many of the injured were transferred to the nearby San Rafael Hospital, which has become inundated with patients, though other local hospitals have sent ambulances to transfer some of the wounded.
“We will request an investigation into the events. (We wish) a speedy recovery for the injured and (send our) solidarity to the families of the victims,” President Ivan Duque tweeted.
President-elect Gustavo Petro urged local officials to ban such events, saying that it was not the first time such an accident had happened.
“I ask mayors not to allow more events involving the death of people or animals,” he said.
Sunday’s event was part of celebrations of the popular San Pedro festival.