A man was in critical condition Wednesday after two state Attorney General’s Office agents shot him at the Greyhound bus station in Downtown Pittsburgh, police said.

Two men began fighting on a bus around 6:40 a.m. and their altercation continued outside on the station’s concourse, police spokeswoman Cara Cruz said. The bus was at the Greyhound station on 11th Street.

Agents with the state Attorney General’s Office were nearby and witnessed one man “threatening the other with a knife, actively trying to stab him,” Cruz said.

The agents ordered the suspect to drop the knife, but he refused.

“In an effort to stop the threat, two agents discharged their duty weapons, striking the suspect in the chest and stomach,” Cruz said.

Cruz did not identify the suspect. An ambulance took the man to the hospital in critical condition and he underwent surgery there, she said.

The other man involved in the fight “struck his head on the ground” during the incident, Cruz said. Medics took him to an area hospital in stable condition for further evaluation.

Pittsburgh police detectives interviewed the bus driver, passengers and other potential witnesses, Cruz said. The investigation is ongoing.

Brett Hambright, a spokesman for the state Attorney General’s Office, said the two agents were from the office’s Bureau of Narcotics Investigation and had been in the area for an unrelated investigation. Hambright did not identify the agents and didn’t say whether they had been placed on administrative leave while the shooting is investigated.

A Greyhound spokesman declined to answer questions about the incident.

“Greyhound is aware of the incident that occurred at the Pittsburgh stop this morning,” said spokesman Mike Ogulnick, in a prepared statement emailed to TribLive. “We are grateful to law enforcement for defusing the situation and we are fully cooperating with their investigation.”

Jim Turoczy works across the street from the bus station. The Greenfield man co-owns Eide’s Entertainment, a store featuring more than 250,000 comic books, memorabilia and more.

Turoczy said his business, which he joined about 44 years ago under previous owner Greg Eide, has more of a problem with homelessness than gun violence.

“We’ve been here 30 years on this block and there’s always been a transient problem,” Turoczy said Wednesday. “This has always been a safer part of the city.”

Mike Staresinic, 58, of Edgewood, said he wasn’t surprised to hear of Wednesday’s incident. He said he went to the Greyhound station late on Nov. 8 to catch a bus to Washington, D.C., but the trip was ultimately canceled. While at the station, though, Staresinic said homeless men and women were sleeping on station benches and a number of people got into arguments, though no fights broke out.

Cruz said Pittsburgh police responded to at least 13 crime reports at the bus station this year through Nov. 6. They included 10 thefts, two aggravated assaults and one robbery.

On Aug. 31, Yan Carlos Pichardo Cepeda, 27, of New York City, was charged with two felony counts of possession with intent to deliver after agents with the state Attorney General’s Office stopped him with 9 kilograms — or 450,000 doses — of fentanyl and a kilogram of cocaine.

A criminal complaint filed in the case said investigators were doing a drug suppression operation at the Greyhound bus station when they spotted Cepeda walking through with a backpack and suitcase.

The bus station is part of the Grant Street Transportation Center, a $50 million building at Liberty Avenue and 11th Street that opened in September 2008. The center boasts two six-story parking garages, the Greyhound station and connections to Amtrak service and Pittsburgh Regional Transit’s Martin Luther King Jr. East Busway.

When the center opened, the Pittsburgh Greyhound station had 34 daily routes and booked about 180,000 passengers annually, a Greyhound spokesperson said.