PROVIDENCE, R.I. (WPRI) — Providence police have confirmed thieves made away with roughly $500,000 in cash and have identified “persons of interest” in a brazen heist early Thursday morning at a Federal Hill bank.

Providence Police Commander Kevin Lanni told Target 12 the bank had a large amount of cash in a vault at the bank at the time of the theft because Santander employees were preparing to stock ATM machines the next day.

“We have video surveillance from inside the bank,” Lanni said. “We have persons of interest.”

He declined to provide more details.

Providence Mayor Brett Smiley said he has been told by police that the theft was “fast and efficient,” and federal law enforcement is also involved in the investigation.

“I know more than has yet been disclosed,” he said during a taping of WPRI 12’s Newsmakers. “It happened quickly and it appears to have been either well planned or someone who knew what they were doing.”

Providence police were called to Santander Bank on Atwells Avenue at 2 a.m. on Thursday. There was no one there when they arrived, but they quickly determined the vault inside the building had been breached in what they described as a “sophisticated” heist.

Target 12 has learned investigators are examining whether the heist was an inside job with someone who had intimate knowledge of the bank and the best time to strike.

The bank was closed on Thursday as investigators swarmed the scene. A post on its website Friday noted it would be closed until Monday.