SAN RAMON — Burglars used a bomb to get into an ATM at a Target store in San Ramon early Sunday morning, prompting an FBI investigation into the break-in and explosion, according to authorities.

No arrests have been announced in the explosive heist, which happened before dawn Sunday at the store on the 2600 block of Bishop Drive off Bollinger Canyon Road, according to the San Ramon Police Department.

Officers were called to the Target at 2:19 a.m. Sunday, and found that an explosive of some sort had been used to get into the store’s ATM, the police department said.

No one was injured. The blast caused damage to the inside of the store’s east entrance, according to police. FBI agents were called into comb through the scene.

Anyone with information about the break-in and blast can contact San Ramon Detective Hugh Cotton at [email protected], or the FBI at [email protected].