Venezuelan riot police fired tear gas Tuesday to break up a demonstration in Caracas called by opposition leader Juan Guaido as he seeks to ramp up demands for elections to replace leftist President Nicolas Maduro.

Riot police moved in quickly to break up the demonstration soon after thousands of protesters began marching a 6km route towards the National Assembly building from the east of the capital.

In the aftermath of the protest, elite FAES police arrested an opposition lawmaker, drawing angry protests from the opposition.

Guaido, recognized as interim president by more than 50 countries including the US, has been seeking to revive mass protests against Maduro which have largely fizzled since spiking early last year.

As the opposition leader attempted to negotiate with a police cordon blocking the path of the march on Tuesday, they fired tear gas at the demonstrators, AFP reporters at the scene said. The march had only progressed a few blocks.

“This picket today does not represent Venezuela, this picket represents the dictatorship,” Guaido said, referring to the line of police with riot shields.

Most of the marchers left the area, but some with their faces covered threw stones at the police.

“A stage of sustained struggle begins today,” Guaido said earlier as he addressed the crowd through a megaphone from the back of a truck.

Lawmakers arrested

The opposition condemned what they said was a heavy-handed FAES raid on a hotel in east Caracas at which opposition lawmakers were staying.

The police “broke into the rooms with deputies inside”, lawmaker Guillermo Palacios told reporters outside the hotel.

They arrested lawmaker Renzo Prieto, who had taken part in the demonstration. Prieto has been detained on two previous occasions. Two other lawmakers with him were also arrested but released.

“They took us, they kidnapped us, they intimidated us, they took away our credentials, cell phones,” one of them, Sandra Castillo, told local media. She added that the incident “is not going to stop us.”

Thousands of protesters had begun the march in east Caracas waving Venezuelan flags and caps in the national colors. Local media reported smaller protests in other cities.

“Today we reconvene in the streets, the place where the citizens are free,” said Guaido in a tweet.

A UN report released Tuesday showed that almost five million people have fled the country’s ongoing economic crisis since 2015.

Guaido blames Maduro for the crippling, five-year economic crisis that has mired the once rich oil-producing country in deepening poverty and soaring inflation.

Pro-Maduro supporters held a counter-demonstration, where they shouted anti-Guaido slogans and called him a “traitor” for enlisting the help of foreign governments to heap pressure on Maduro’s regime, particularly in the form of sanctions.

Plunging oil prices in world markets Tuesday are the latest shock to the economy, which is almost entirely dependent on revenues from its declining, sanctions-battered oil industry.

“It’s 30 years since prices fell like this, it’s a tragedy,” said Guaido in reference to Monday’s plunge that took almost one-third off the price of oil.