Two fans died during a stampede at South Africa's FNB Stadium during Saturday's Soweto derby between Kaizer Chiefs and Orlando Pirates in Johannesburg, police told state broadcaster SABC.
Johannesburg public safety official Michael Sun also said on Twitter that two deaths had been confirmed, along with multiple injuries. One person was critically injured and 16 others had minor injuries, the stadium management said in a statement that also confirmed it is conducting an investigation with police.
The stampede occurred at the stadium's Gate J, police said, during the Carling Black Label Cup final between South Africa's two biggest sides. The venue previously hosted the 2010 World Cup final.
Eyewitness News quoted Sun as saying that the alleged cause of the stampede was linked to disruption caused by people trying to sell or present fake tickets at a stadium gate.
"It's a tragedy in probably one of the biggest games of the season," Sun said. "It's certainly very sad, there have [also] been reports of several injuries as a result of the stampede."
"This sad loss of life at such a highly anticipated event is indeed a tragedy," added Johannesburg mayor Herman Mashaba, "and the city will work with all the relevant authorities to prevent tragedies such as this in future."
The match, which heralds the start of the South African season, went on as planned, with Chiefs claiming a 1-0 victory after Bernard Parker's 10th-minute winner.
Jacques Grobbelaar, the CEO of Stadium Management South Africa, told journalists in the postmatch news conference that all measures had been taken to avoid such an incident.
"We wish to express or condolences to the families of all those who are affected by the incident today," he began, as shared by Orlando Pirates on their official Twitter handle.
"This is extremely unfortunate as solid security plans were in place to ensure that this is a risk-free event.
"At kickoff, there was no reason to believe that the game needed to be delayed, given that the stadium was half full."
The incident comes just a fortnight after eight supporters were killed and a further 49 injured after a wall collapsed following a fight between rival fans during the Senegalese League Cup final at the Stade Demba Diop in Dakar.
In April 2001, 43 supporters were killed in the Ellis Park Stadium disaster -- also during a Soweto derby between Chiefs and Pirates -- in an incident that remains South Africa's biggest sporting tragedy.