GARY, Ind. — One person was killed and an ATF agent was wounded, in an apparent shootout Thursday afternoon in Gary, Indiana, reports CBS Chicago.

Lake County Prosecutor Bernard Carter said he was notified an ATF agent was shot in the chest in a shootout near 25th Avenue and Broadway. Another person involved in the shooting died.

Brendan Iber, assistant special agent in charge of the ATF Chicago field division, the agent was in critical but stable condition after being shot multiple times. He had been working an undercover operation when he and other agents were "ambushed," Iber said.

BREAKING: ATF’s Chicago Field Division is responding to an agent being shot during an operation in Gary, Ind. pic.twitter.com/G94cTtBvLb — ATF HQ (@ATFHQ) June 7, 2018

The agent's name and details of the injury were not immediately released. Neither was the name of the deceased person.

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Sources tell CBS News that the veteran ATF agent was assigned to the joint gun task force with Chicago police. He was apparently not wearing a bulletproof vest and was shot in the arm and the chest, the sources said.

He is currently expected to survive.

This is a developing story.