An Argentine journalist and two of her British colleagues were detained by the Venezuelan military on Friday at the northwestern border with Colombia, the national press union (SNTP) said.
Argentine Laura Saravia along with Brits Barney Green and Dan Rivers were held "as they left the country," the SNTP said on Twitter.
It said their whereabouts are unknown but claimed they had been "in Venezuela for three days reporting on tourism."
Three people hired as security by the journalists were arrested on Wednesday, the SNTP said.
All three state on their social media accounts they work for British television production company ITN.
Rivers was previously a CNN correspondent in London and Bangkok, according to his Linkedin account, while Saravia has worked for the BBC and NBC.
Cameraman and editor Green worked for Sky News in London and Washington, according to his Linkedin profile.
Several foreign journalists have been deported by Venezuelan authorities in recent years as they didn't have permits authorising them to work in the country.
Venezuela has attracted a great number of foreign journalists looking to report on its economic and political crises during four years of recession under President Nicolás Maduro.
Citizens face shortages of basic necessities such as food and medicines and failing public services such as water, electricity and transport.
It has resulted in 1.6 million Venezuelans fleeing the country since 2015, according to the United Nations.
Organizations such as SNTP have accused Maduro's government of violating press freedom through the closure of media outlets, censorship and the restriction of paper deliveries, which are monopolized by authorities.
For his part, Maduro has accused international media organizations of being mouthpieces for a United States-backed campaign involving the opposition to overthrow him.