Hundreds of Venezuelans swept up in President Donald Trump's immigration dragnet have reached home after their release from a maximum security Salvadoran jail as part of a prisoner swap with the United States.

The 252 men were accused without evidence – of being gang members and flown to the notorious Cecot "anti-terror" jail in March.

There, they were shackled, shorn and paraded before cameras – becoming emblematic of Trump's immigration crackdown and drawing howls of protest.

On Friday, after months of legal challenges and political stonewalling, the men arrived at an airport near Caracas, with several walking down the steps with their arms raised and one even kissing the tarmac.

The Trump administration said they were released in exchange for 10 Americans or US residents held in Venezuela, and "political prisoners", who number 80, according to El Salvador President Nayib Bukele.

The migrants' return to Venezuela sparked tearful celebrations among family members who had heard nothing from them in months.

The men had been deported from the United States under rarely used wartime powers and denied court hearings.

Exiled Salvadoran rights group Cristosal believes that just seven of the 252 men had criminal records.

Venezuelan leader Nicolas Maduro thanked Trump for "the decision to rectify this totally irregular situation."

The Americans and US residents released in Venezuela, whose identities have not been officially revealed, were taken to San Salvador on their way to the United States and appeared with Bukele and US hostage envoy Adam Boehler at a ceremony at the presidential palace.

A video posted on X by Bukele shows the former detainees waving US flags as they descended from their aircraft. (AFP)