Two people were arrested in connection with the mass shooting Saturday in Philadelphia in which three were killed and at least 11 injured, Fox 29 reported.

Rashawn Vareen was charged with attempted murder and aggravated assault, while Quran Garner was also charged with aggravated assault and assault on law enforcement officers.

The first shot in the melee was apparently fired by Gregory Jackson, 34, and critically wounded another man. The second gunman managed to return fire, with the two exchanging 17 rounds, during which Jackson was killed.

The other two fatalities were innocent bystanders: Kristopher Minners, 22, and Alexis Quinn, 27.

Jackson and the second gunman were licensed to carry firearms. The second shooter was not charged because police said he acted in self-defense.

The DA's Office said several of those connected to the shooting are apparently part of the local boxing scene, according to 6ABC.

District Attorney Larry Krasner said at least four weapons — three 9 mm weapons and one 40-caliber firearm — were involved in the incident, and it's possible that more guns involved.

Krasner visited the scene of the mass shooting and called it “chilling,” adding that "no less chilling is that it happened in more than 10 places around the country over the space of a few days."

Authorities said the officer who shot his weapon during the incident was placed on administrative duty pending the outcome of the investigation, as per protocol, 6ABC reported.

"Our hearts are heavy today with the passing of Kris Minners, a second-grade boys' resident adviser at Girard College and member of [the Federation of Teachers] union, yet another victim of senseless gun violence. Our thoughts are with Mr. Minners' family who woke up this morning missing someone at their breakfast table, his colleagues who will be without a friend, and with his students who will be without a mentor and a role model," the union said in a statement.

Philadelphia Police Commissioner Danielle Outlaw called it "a dark day" for the city when many people out enjoying a beautiful day were victims of "horrendous and unthinkable acts ... in a very popular local and tourist hangout," according to 6ABC.

He added that “it's important that we bring justice to the victims, their families, and our community."

Philadelphia Mayor Jim Kenney said that "it's gotten to the point where there's no price to pay for carrying illegal guns, so people carry them because they don't think anything is going to happen."

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