CHICAGO – An armed gunman barricaded himself inside a bank on the city’s North Side Thursday morning, and police were trying to determine if he was holding hostages.

The robbery of First Commercial Bank was reported to police at 9:42, and when officers arrived, they found what Chicago Police Superintendent Dana Starks called a “hostage situation.” But some of those inside the bank had gotten out, and Starks and William Monroe, assistant special agent in charge of the FBI’s Chicago office, said it remained unclear if the gunman was holding anyone.

Television footage showed police escorting several people who had been in the bank. The people had their hands on their heads and were frisked by officers, presumably to ensure the robber or robbers did not try to sneak out of the bank with the customers or employees.

At the same time, Monroe said agents were trying to establish contact with the gunman.

Authorities blocked off area streets and told several businesses to shut their doors and close down until the standoff had ended.

“It was very confusing and shocking,” said Cristina Santana, a waitress at La Cazuela Mexican restaurant across the street from the bank.