MADRID, June 19 — Cuba’s state security is pressuring dissidents to go into exile in its attempt to weaken opposition on the Communist-run island, a non-governmental human rights organization said Wednesday.

The Madrid-based Cuban Prisoners Defenders released a 259-page report that named 35 activists, independent journalists and artists whom authorities had forced to leave the country over the past two years, telling them never to return.

State security threatened them with prison or bodily harm if they did not leave and harassed their families, said the NGO, which has links to Cuba’s largest opposition group, the Patriotic Union of Cuba (UNPACU).

Cuba’s government, which did not reply to a request for comment, accuses dissidents of being mercenaries paid by its longtime Cold War foe the United States to undermine it and typically dismisses such charges as attempts to tarnish its reputation.

“It is evident that this is something happening on a massive and alarming scale and that is it imperative it be stopped,” Cuban Prisoners Defenders said in the report, which included dozens of case testimonies.

The NGO, which formed late last year, said more than a third of the 26 activists who responded to its online survey said they were escorted to the airport by state security and forced into exile.

Some were given boarding passes, typically for flights to Guyana, where Cubans can get a tourist visa on arrival, and money for their first month, it said.

The group said that during an eight-day survey period this month, it identified 42 more people whom state security forces were pressuring to leave and concluded there were likely many more cases.

Cuban Prisoners Defenders representative and UNPACU member Javier Larrondo said Cuban authorities had long encouraged some dissidents to leave but were becoming more systematic and aggressive, partly to bring down the number of political prisoners in jails.

“I intend to get to the United States because it is the country that most offers us security,” one of the activists named in Wednesday’s report, Eliecer Gongora Izaguirre, told Reuters by telephone from Costa Rica.

The 37-year-old said state security escorted him to the airport to board a flight to Guyana in February, forcing him to leave behind his wife and four children.

Previously he had been imprisoned for six months and his family had faced continuous harassment for his activism in UNPACU, he said. That included having their home expropriated and his children being taunted at school, he said.

A Havana-based Western diplomat, who spoke on condition of anonymity, said the state tended to pressure little-known activists rather than high-profile figures, which would more likely spark international outcry.

Gongora Izaguirre said that from Guyana, he crossed the border to Brazil and Peru, from where he started a perilous trek north on buses and by foot, through jungle and across rivers through Ecuador, Colombia and Panama to Costa Rica.

He knows finding refuge in the United States will be hard because the Trump administration has cracked down on asylum seekers.

“I’m not going to give up the fight,” he said. “I’ll only give it up when I’m dead.”