Police are investigating the explosion of a small pipe bomb that exploded at the Holladay Bank and Trust, 2020 E. Murray Holladay Road, early Saturday morning.

The "small explosive device" broke a small hole in the glass in the drive-up teller's window when it exploded about 3:45 a.m., but the extent of the damage is not yet known, said Salt Lake County special agent, John Minichino.Neighbors who live near the bank heard the explosion. "It was loud enough to wake us up," said Wayne Jensen. "We thought it might have been a car wreck."

Brandon Pehrson said he saw glass spread all over the parking lot when he and his father drove up to an office building near the bank at 7:30 a.m. "I saw glass all the way up to the street (about 50 yards away). There was a handkerchief in the driveway and bolts laying next to it, so my dad called the police," he said.

Due to a number of similar pipe bombings in the past couple of weeks, Salt Lake Police called in the Salt Lake Fire Department and the Salt Lake County Sheriff's Department to investigate.

"We won't know if there is a connection with any of the other bombings until we conduct interviews to find out what happened," said Minichino.

No one was injured in the explosion.