Chicago police were searching a bank on Chicago North Side on Thursday where a gunman took hostages, who were later released.

FBI spokeswoman Cynthia Yates said about six hostages had been taken and that all of them had been released. She had no information on the suspect, and Chicago police said no arrests had been made.

The robbery of First Commercial Bank was reported to police at 9:42 a.m., and when officers arrived, they found what Chicago Police Superintendent Dana Starks called a "hostage situation."

SWAT officers were seen entering the building, and leaving a short time later. Chicago Police spokeswoman Monique Bond said the search of the building was continuing.

One of those inside the bank was Young Kim, the owner of a nearby store who said he was in the bank making a transfer when the robbery occurred, and left almost immediately.

"I'm scared," the 48-year-old Kim told the Chicago Tribune. "I could've been in there when they came in the bank."

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.

Authorities blocked off area streets and told several businesses to shut their doors and close down until the standoff had ended. Two nearby schools — The Chicago Mathematics and Science Academy and Newfield Primary Center — were also on lockdown.

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