Venezuela on Tuesday was set to expel a crew of Al Jazeera journalists who were intending to cover an opposition march against President Nicolas Maduro, the country's union of journalists said.

With Venezuela in the throes of severe economic and political crises, the opposition has called for a march on Caracas on Thursday to press its constitutionally sanctioned demand for a referendum to remove Maduro.

The authorities detained three employees of the Qatar-based channel when they arrived Monday at Maiquetia international airport outside Caracas, the National Union of Press Workers (SNTP) said on Twitter.

"Teresa Bo, correspondent, Lagmi Chavez, producer, and a cameraman (from) @AlJazeera were detained in Maiquetia," the SNTP tweeted, saying their equipment was confiscated.

The cameraman was named in local media reports as Mariano Rosendi.

The journalists travelled from Argentina but are to be deported to Colombia, the SNTP added.

Media rights groups frequently criticize Venezuela for violating the freedom of the press. One local group, Espacio Publico, registered 286 incidents last year, mainly in the form of intimidation and harassment.

Reporters Without Borders ranked the country 137th out of 180 last year on its worldwide press freedom index.

Source: AFP