The Salvadoran government has been accused of widespread abuses as it waives civil liberties to combat gang activity.

In a Twitter post on Friday, President Nayib Bukele celebrated the arrival of the alleged gang members at the prison, which has space for 40,000 people and is said to be the largest in the Americas.

“At dawn, in a single operation, we transferred the first 2,000 members to the Center for the Confinement of Terrorism (CECOT),” said Bukele. “This will be their new house, where they will live for decades, all mixed, unable to do any further harm to the population.”

Bukele and his allies passed a controversial “state of exception” last year, suspending key rights such as the right to a lawyer and the right to private communication. The declaration also allowed police to make arrests without a warrant and without explanation.

Human rights groups have criticised the measures, accusing the government of empowering itself to act with impunity with little recourse for the wrongfully imprisoned. Dozens of imprisoned people have died during the state of exception, which has been extended several times.

However, the crackdown has garnered widespread support from Salvadorans. Many credit the measures with curbing the criminal gangs that have inflicted campaigns of violence and exploitation on entire neighbourhoods for decades.

In a February article, the Salvadoran paper El Faro, which has reported on the alleged abuses during the state of exception, said the government had dealt a serious blow to the gangs, even as it questioned how durable those changes would be.

“Critics of the state of exception admit, with nuance, that it has produced tangible results for the population,” the article reads. “But they focus the discussion on the future: How will these organizations mutate? How sustainable are the achievements of a policy of repression?”

Some critics also asked what would happen when those who had been arrested were eventually released from prison.

On Friday, Bukele and his allies seemed to offer a reply: They won’t be.

“We are eliminating this cancer from society,” justice and security minister Gustavo Villatoro said on Twitter. “Know that you will never walk out of CECOT, you will pay for what you are … cowardly terrorists.

The complex, located about 74 kilometres (46 miles) southeast of the capital San Salvador, is made up of eight buildings, each with 32 cells that hold more than 100 people apiece. A single cell, however, only has two sinks and one toilet.

The prison’s warden, wearing a ski mask to protect his identity, told journalists when the project was unveiled that the cells will not include mattresses.