Three men were arrested on Friday for allegedly attacking a nurse during a vaccination drive against measles and rubella in Kerala’s Malappuram district a day earlier, The Indian Express reported.

The men who attacked nurse Shyamala Bai were part of a group of people protesting against the government-sponsored vaccination drive at a school Edavur. The group allegedly tried to twist her hand and smashed her cellphone. The police said they attacked other members of the medical team, as well.

The attackers were mostly parents and relatives of the children being vaccinated. “They entered the school and were talking to the doctors and nurses,” Prateesh Kumar, a senior police officer, told NDTV. “The discussion got heated, and the group began to attack health officials.”

According to the police, an anti-vaccination lobby has been sending messages on social media to convince the residents of the area to not take part in the drive, The Indian Express reported. Some of these messages claim that the vaccines lower life expectancy among children, according to NDTV.

“Strict action will be taken against those who stopped the vaccination drive and are spreading fear in society,” District Collector Amit Meena told The Hindu after the nurse’s assault. Kerala Health Minister KK Shailaja said such incidents “should be seen in isolation, with no support from the public”.

The police said the nurse was taken to a hospital in Kuttipuram and was out of danger.