Police say two Palmeiras fans have been shot before a Brazilian league match in Sao Paulo.

Police said Sunday that one person was hospitalized in serious condition and was undergoing surgery after being hit in the waist region, while the other was recovering after being hit in the leg.

Police officer Thiago Cesar told the SporTV channel it remained unclear who fired the shots, which came after supporters from Palmeiras and Corinthians got into a confrontation just outside the Prudentao stadium in Presidente Prudente.

Police had to fire rubber bullets to keep the situation from escalating.

Palmeiras and Corinthians have waged the Paulista Derby 337 times, the first match having taken place in 1917.

Palmeiras came back to win Sunday's match over their league-leading city rival, 2-1, their 121st victory in the derby's history.