Senior sports officials insisted on Monday that safety would be a priority at Brazil's upcoming football World Cup and Olympics, in the wake of a nightclub fire that killed 231 people.

"What happened is the most horrible thing that can happen," Jerome Valcke, secretary general of football's governing body Fifa, told reporters in Brazil after Sunday's deadly inferno in the southern town of Santa Maria.

"However, it has nothing to do with the security within the stadiums," he said, ahead of the Fifa Confederations Cup to be held in Brazil June 15 to 30 and the Fifa 2014 World Cup to be staged here next year.

"We have an emergency plan in place to evacuate a full stadium within eight minutes," he added.

"There are dedicated people in charge and trained for disaster management as part of the overall security concept," he said, insisting that what happened "cannot be compared to the organisation of the Fifa World Cup security plan."

While expressing his condolences to the families of those who perished in the tragedy, Valcke underscored his faith in organisers of both events.

"We have full confidence in the local organisational committee and the authorities. We are just sad for the families of the victims."

In Lausanne, a spokesperson for the International Olympic Committee also stressed that safety was a top priority for all involved in planning and staging the 2016 Summer Games in Rio, scheduled for August 5 to 21, 2016.

"We are working in close cooperation with the organising committees of the Games to assure ourselves that the safety rules meet international standards," the spokesperson said.

"We do not doubt that Rio 2016 will offer a secure environment for the fans, athletes and those working for the Games."

Carlos Villanova, director of communications for Rio 2016, said the fatal nightclub fire could have happened anywhere in the world.

"It has nothing to do with Brazil's capability to organise large scale events as has been shown over decades with the Rio Carnaval and the New Years fireworks on Copacabana beach" that each year draw up to two million people without incident, Villanova said.

As families and friends held the first funerals for their loved ones who perished in Santa Maria, police said they had arrested the owner of the nightclub, as well as two musicians who starred in an ill-fated pyrotechnic show.