Families in a Massachusetts city are raising concerns after anti-vaccine protesters reportedly harassed parents and children outside of a COVID-19 vaccination clinic held at a school.Sarah Sloan told NewsCenter 5 that the alleged harassment happened outside the Gardner Middle School on Tuesday, while about 180 children between the ages of 5 and 11 received COVID-19 vaccines there."People were having things thrown at them. Water bottles, things thrown at their cars," said Sloan, who brought her 9-year-old daughter and nieces to the middle school for the clinic.According to Sloan, someone forced a flyer onto her that read the COVID-19 vaccine is not safe and is highly effective at causing injury."He was looking right and the children and he said: 'You know, your mom is taking you in there to give you something that could potentially kill you,' and 'This vaccine makes children's hearts explode,'" Sloan said. "He just kept saying: 'It'll make your heart explode.' Over and over again. Now, the children are visibly upset, they're screaming. They're freaking out I'm trying to console them and also tell him to back off."Chris Richard, who brought his younger cousin to the middle school clinic, said that there were five anti-vaccine protesters gathered at the school's sign. Richard took a video of the protesters, which showed some of them carrying signs and one holding a bullhorn."The guy was screaming at my little cousin, who is only 9, who just got vaccinated, 'Oh, I hope you're going to be OK now that you got that vaccine,'" Richard said. "My cousin was scared when she got home. She said: 'Oh, am I going to be OK? Why were they out there screaming?' She was scared."Dr. Mark Pellegrino, superintendent of Gardner Public Schools, said the protesters had a First Amendment right to be there, but he called the police when he heard they were blocking traffic and scaring children."Someone else took one of the fliers and pushed in a child's face. The child is probably 6 years old or so," Pellegrino said. "If you want to say something to parents and you want to have your posters, that's fine. But do not approach my children.""It may be a little bit more understandable if this was an adult vaccine clinic, but this was only for children," Sloan said. "Their prime goal, in my opinion, they were there to terrify these poor kids, because the things that were coming out of their mouths were monstrous."Families who spoke with NewsCenter 5 said their children are doing well after receiving their COVID-19 vaccines.No arrests were made during the vaccination clinic.