Red flags hang outside homes in Apia, Samoa, indicating that the residents have not been vaccinated for measles.

Samoan authorities have arrested a prominent anti-vaccination activist amid an outbreak that has killed at least 63 people, most of them children.

Edwin Tamasese has been charged with “incitement against a government order,” according to the BBC.

Government officials say anti-vaccination advocates such as Tamasese have complicated their sweeping efforts to turn the tide on the highly contagious disease that has sickened more than 4,300 people on the independent Pacific islands.

The government has declared a state of emergency and ordered mandatory vaccinations. It shut schools indefinitely. This week, it launched a door-to-door mass vaccination campaign, asking families to pin a piece of red cloth on their homes if they haven’t been vaccinated.

On Thursday and Friday, the government closed all of its offices except public utilities, so that civil servants could focus on the campaign. Officials say more than 20,000 people have received vaccines.

“Let us work together to … convince those that do not believe that vaccinations are the only answer to the epidemic. Let us not be distracted by the promise of alternative cures,” Prime Minister Tuilaepa Sailele Malielegaoi said earlier this week.

The anti-vaccination movement “unfortunately has been slowing us down,” Samoa’s minister of communication, Afamasaga Lepuiai Rico Tupai, told New Zealand’s 1 News Now.

Tupai blamed “anti-vaxxers” for the deaths of children. “We find out it’s the message of anti-vaxx that’s got to these families. … What we say to them is, ‘Don’t be in the way of government. Don’t be contributing to the deaths and the numbers rising.’ “

As Tamasese was being taken into custody, he spoke out again on social media against the vaccine, falsely claiming that a combination of vitamin C and sodium ascorbate, a mineral salt of ascorbic acid, can cure the disease. “This will save your kids,” was posted on Facebook before, he said, authorities took his phone.

Response to Tamasese’s arrest has ranged from support from people who call him a hero to derision from critics who accuse him of worsening a deadly crisis.

“In jail for somthing he said? Do you all not see somthing wrong with this?” one Facebook user said. Another called for significant penalties: “Spreading antivaxx propaganda and lies which endangers children in the middle of an epidemic. He should be locked up for good.”

Samoa’s attorney general told Stuff that authorities were responding to the following statement Tamasese allegedly made about the government’s vaccination campaign: “I’ll be here to mop up your mess. Enjoy your killing spree.”

In a speech on Thursday, Simona Marinescu, the United Nations resident coordinator for the region, called the outbreak “one of the greatest challenges that this country experienced in its recent history.” Last week, the Samoan government asked the U.N. for help in controlling the epidemic.

Vaccination rates in Samoa have dramatically dipped in recent years, according to a new report from UNICEF. Coverage “plummeted from 58 per cent in 2017 to just 31 per cent in 2018, largely due to misinformation and mistrust among parents.” UNICEF says vaccination rates of at least 95% are needed to prevent outbreaks.

The government’s campaign has given that effort a huge boost. It said that as of Thursday, 82% of children under 5 on Samoa’s two main islands are vaccinated.

Samoa’s crisis comes during a global resurgence of the preventable disease. The World Health Organization estimates there were nearly 10 million measles cases last year — and 140,000 deaths.

NPR’s Bill Chappell contributed to this report.

Correction Dec. 6, 2019

In a previous version of this story, several references to Edwin Tamasese’s last name were incorrectly spelled Tamesese.