More than 2,000 people have been arrested in Venezuela for political reasons since the beginning of the year, most of them detained during anti-government protests, an NGO reported Tuesday.

“Between January 1 and the month of May 2019, 2,014 persons have been arrested, the majority of them protesters,” said Alfredo Romero, head of Venezuela’s Foro Penal prisoners’ rights NGO.

More than 800 are still in detention, Romero told a press conference.

Protests have proliferated throughout Venezuela since opposition leader Juan Guaido proclaimed himself acting president on January 23.

Tensions increased last week when Guaido called for an uprising by troops loyal to President Nicolas Maduro.

Romero said 339 people were arrested after the failed uprising and the demonstrations that followed on April 30 and May 1, adding that 82 were still in jail.

On Monday, Venezuela’s Attorney General Tarek William Saab said 233 people were arrested in the protests sparked by the failed uprising.

Venezuela has suffered five years of recession that has seen more than 2.7 million people flee poverty and insecurity since 2015, according to United Nations figures.

Of the 30 million people left behind, the UN says almost a quarter are in desperate need of humanitarian aid.