A late-night scuffle outside Denver's football stadium after the Broncos' 27-20 loss to the San Diego Chargers on Thursday left three people with stab wounds -- one of them in critical condition, authorities said Friday.
Police had three people in custody, authorities said Friday.
A fourth person may also have been injured in the incident in the parking lot next to Sports Authority Field at Mile High, Denver Police Sgt. Steve Warneke said. That person left without seeking treatment, according to authorities.
The other two known victims were in stable condition, police said.
It wasn't clear what set off the 10 p.m. (12 a.m. ET) incident.
The Denver Broncos referred questions to Stadium Management Company, which runs the team's stadium. The company said it was aware of the incident and was working with authorities.
This is second violent incident after a Broncos game this month.
A 30-year-old man died after he fought another person in a parking lot near the Kansas City Chiefs' Arrowhead Stadium on December 1. That incident happened after a game between the Chiefs and the Broncos.
-- CNN's Chuck Johnston contributed to this report.
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