The bakery had been wrecked by vandals last week - only two weeks after it opened - and it had taken 30 to 40 people to clean it up.
On two separate occasions before opening, someone had driven past and shot at the windows, once while the owner was inside.
He suspected he knew who the culprits were, and believed it was the same people each time.
When asked whether he had been approached or warned to leave the area, he declined to comment.
"Police are working on it," said a friend of the owner.
"The security has been bulked up ... hopefully it doesn't happen again."
The friend asked for members of the public to keep an eye out for anything suspicious.
"The poor guy's been doing business for two years in Wanganui," he said.
"It's saddening to see this happening to him."
The owner said he provided the best service he could for the community.
"I'm just upset what they have done," he said.
He wanted to thank all the members of the public who helped with the clean-up, and who were offering words of support when they came into the bakery.
"Thanks for everybody who's been supporting us all along."
Two girls living across the street heard two bangs as the windows were smashed and ran to the door to see a white car speeding away down Ingestre St.
"I described it as a little granny car," said one of the girls.
They did not see who was in the car, and weren't sure whether it was related to the window smashers.
Mayor Annette Main said she was "disturbed" at the continuing attacks on the bakery.
"What appears to be occurring has no place in a caring and safe community," Ms Main said.
"Not only must it be very upsetting for the proprietors but also for those who live in the area.
"People deserve to be able to live and run a business in our community without any fear of intimidation.
"I urge anyone with any information to pass it on to the police."
Members of the public with information can contact the Whanganui Police Station on 06 349 0600.
Information can also be provided anonymously via Crimestoppers on 0800 555 111.
If you witness a crime happening, call 111.