Barquisimeto, Venezuela - Relatives of Venezuelan sent by the US to a Salvadoran prison protested Saturday for their release, joining other families who said they were "deceived" in believing they were headed back home.

Over 200 Venezuelans on March 16 to a maximum security prison and forced labor camp in El Salvador, after President invoked wartime powers to expel people who were accused of being gang members.

The decision has triggered a legal standoff in Washington as the administration ignored a judge's order , and in Venezuela it has sparked outrage among family members.

The Trump administration argues that the 238 were members of the violent Tren de Aragua gang – offering very little evidence – but Venezuelan relatives insist that many of those shipped to El Salvador without trial were not criminals and were in some cases tricked into surrendering.

"How come so many people said they were coming to Venezuela and today they are in El Salvador?" demanded Gladys Coromoto Rojas, grandmother of deportee Kenlyn Rodriguez.

"They were deceived," she told AFP at a street protest in the city of Barquisimeto, some 266 miles west of Caracas.

The family of 36-year-old Maikel Rojas Olivera explained that he had been in touch to tell them he was coming home to Venezuela on Saturday, only to be shipped to El Salvador.

Olivera was detained by the US Immigrations and Customs Enforcement (ICE) agency in October last year.

He was initially held at a detention center in California until March 7, when he was transferred to Texas, to be flown on to El Salvador.

"We demand that they bring all those innocent boys from El Salvador to their country," his sister said.

The protest was joined by about 80 people, including relatives and neighbors of the migrants.

The Venezuelan government has called the detention of Venezuelan migrants in El Salvador a kidnapping and announced the hiring of a law firm to manage their return to the country.