Spanish reporter Gonzalo Domínguez, center, is seen Thursday after his release from government custody in Caracas, Venezuela. He is flanked by Spanish Deputy Consul Julio Navas, second from left. (Miguel Gutierrez/EPA-EFE/Shutterstock)

The Venezuelan government has stepped up efforts to quash news coverage of an opposition effort to overthrow President Nicolás Maduro, arresting at least 10 journalists over the past week in moves that have drawn protests from the European Union and Spain.

All were subsequently released or deported.

Two foreign journalists covering the developments for the Spanish news agency EFE were detained at their hotel Wednesday evening by rifle-toting internal security police. The crackdown comes as Maduro faces the strongest challenge so far to his grip on power.

Spanish reporter Gonzalo Domínguez and Colombian producer Maurén Barriga Vargas were taken to the Helicoide — a notorious jail where political prisoners are usually held.

Another EFE journalist, Colombian photographer Leonardo Muñoz, and his Venezuelan driver, José Salas, were detained earlier Wednesday as they covered a small pro-government gathering.

After more than 12 hours in custody, the three EFE journalists were freed Thursday and were given credentials to continue reporting, according to the news agency’s website. A union for Venezuelan journalists had reported earlier that the Spaniard and two Colombians were slated to be deported.

The government has intensified suppression and intimidation of journalists in recent days by ordering newsrooms to avoid covering opposition rallies and speeches, closing down radio stations, raiding TV channel offices, and blocking websites.

Of the 10 journalists who were arrested, six have now been freed, and four have been deported. Salas, the driver for the EFE photographer Muñoz, was also released Thursday.

Venezuela is going through a tense period as Maduro’s government faces the biggest challenge to his rule since he rose to power in 2013 after the death of his mentor, leftist firebrand Hugo Chávez.

Opposition leader Juan Guaidó, backed by the Trump administration and a slew of foreign governments, declared himself interim president and was sworn in last week. He is propelling anti-government demonstrations even in former pro-government strongholds.

Reporting a raid Thursday that further raised tensions, Guaidó said members of a national police anti-gang unit, the Special Actions Force (FAES), descended on his home while he was out and were looking for his wife, Fabiana. He said their 20-month-old daughter was there at the time and that he would hold Maduro responsible if anything happened to her.

Sen. Marco Rubio (R-Fla.) tweeted that Maduro’s “shock troops” arrived at the apartment when Guaidó’s daughter was at home with her grandmother. “Clearly this was effort to intimidate him & the opposition,” Rubio wrote.

After going to the apartment building with his wife to pick up their daughter, Guaidó told reporters that FAES members arrived in a white van and on two motorbikes and asked for his wife. “The objective is very evident,” he said. “They’re trying to intimidate us. They’ve assassinated minors and kidnapped children. Since they weren’t able to intimidate the people, they won’t intimidate this Venezuelan family.”

In a speech at the Central University of Venezuela before the incident, Guaidó outlined a plan to address the country’s “humanitarian emergency” and “recover the oil industry” as a way to revive the economy.

“This plan does not intend to tighten belts but to recover, reactivate and look for new sources of income for the country,” he said.

This week, the United States imposed sweeping sanctions on state-owned oil company Petroleos de Venezuela S.A. (PDVSA), the crown jewel of the Venezuelan economy, blocking the government’s main revenue stream, and froze all Venezuelan government accounts in U.S. banks, saying the money belonged to the new government.

Venezuelan Foreign Minister Jorge Arreaza said on Twitter that the detention and expulsion of foreign reporters was necessary because they entered the country without visas required to work as journalists. But experts said that explanation is not supported by Venezuelan law — or the facts.

“The argument they’re giving is that they didn’t have credentials,” said Nélida Fernández, EFE’s Venezuelan bureau chief. “But when they arrived in the airport, the intelligence police approached them, and the reporters told them that they came here to work. They even had photography equipment with them. And the police authorized them to come in.”

On Tuesday night, two Chilean journalists for the TVN station and two Venezuelans were caught near the presidential palace in central Caracas and kept for at least 10 hours. For the first five hours, no one knew where they were.

Rodrigo Pérez and Gonzalo Barahona were deported to Chile on Wednesday night, and Maiker Yriarte and Ana Rodríguez, both broadcast reporters, were freed. They told the journalists union that they were not physically mistreated but were insulted and that their documents were seized.

Two French journalists, Pierre Caillet and Baptiste de Monstiers, were detained Tuesday night while covering a small pro-government rally. On Thursday morning, they were sent to the airport in Caracas to board a flight back to France, according to Romain Nadal, the French ambassador to Venezuela.

Venezuelan journalists have also had to limit their coverage. Well-known radio presenter César Miguel Rondón, whose daily program has been on the air for 30 years, was forced to shut down.

“Censorship had never been as tough as we’re seeing this week,” Rondón told The Washington Post on Wednesday.

On the night after Guaidó swore himself in as president on Jan. 23, Global TV in northwestern Venezuela was raided and its equipment destroyed. Another station was also forced to close.

“We’re now off air and don’t know what we’re going to do,” said Guido Briceño, Global TV’s owner.

Traditional TV networks follow specific guidelines to avoid being closed or placed under sanctions, journalists said. Guaidó cannot be interviewed, described as “president in charge” or called “president of the National Assembly,” said a reporter with the Venevision TV station who declined to share his name for fear of losing his job. “We can only call him Juan Guaidó.”

Krygier reported from Miami.