A man was in custody after he allegedly ignited an explosive device and threw it under a sheriff’s patrol car parked outside a grocery store in Sonoma County on Friday, the local Sheriff’s Office said.

The incident occurred around noon as the deputy driving the car was stopped for lunch at the Safeway in Guerneville, an unincorporated community in the Russian River Valley, according to a sheriff’s news release.

The deputy was inside the store at the time and was unharmed.

While shopping, the deputy heard a loud explosion that rattled the store’s windows. When he ran out to see what happened, he saw a commotion surrounding a man being chased by an off-duty officer, officials said.

The off-duty officer managed to tackle the man and held him until the deputy was able to handcuff him.

Witnesses later told investigators they had seen the man lobbing “suspicious items” underneath the patrol vehicle, according to the release.

One of those bystanders was an employee at the grocery store who suffered minor injuries. She was able to return to work after being treated at the scene, and no one else was hurt.

The suspect was in possession of a backpack that authorities believe contained additional explosives. As a result, the Safeway and surrounding neighborhood were evacuated, and the suspect was taken away from the scene, officials said.

The sheriff’s bomb squad responded and neutralized the bag, authorities said. The parking lot remained closed, however, as a bomb-sniffing K-9 searched the area and suspect’s car for any additional explosives.

The Sheriff’s Department noted it was a “busy tourist weekend” in the town, and said other areas were considered safe. The Safeway would be open with limited access.

Officials were not releasing the suspect’s name but said he was believed to be a Sonoma County resident.

Authorities were continuing to investigate, and no further detains were available.