The new head of Venezuela’s congress was pulled from his vehicle and briefly detained by police.
The confusing incident is bound to ramp up tensions between the opposition and government following President Nicolas Maduro’s swearing in for a controversial second term this month.
It came a day after the US-backed Juan Guaido assuming the presidency as a way out of the country’s deepening crisis.
A video circulating on social media purports to show the moment in which Mr Guaido is intercepted on his way to an anti-government “Citizens’ Meeting” in the port city of La Guaira.
In the video shot on a mobile phone by a motorist stuck in traffic, several men in ski masks and carrying assault weapons are seen struggling to shut the door on someone being pushed into a vehicle before racing down a road.
While it was not possible to identify Mr Guaido in the 33-second video, his wife said on Twitter that he had been detained by a commando unit of the feared SEBIN intelligence police. As news of his detention spread, he was then released.
“I thank everyone for the quick response in the face of abuse against my husband by the dictatorship,” Fabiana Rosales said in a message posted on Twitter. “The dictatorship will not be able to bend his fighting spirit.”
Adding to the confusion, the government tried to shift the blame to Mr Guaido’s allies, with communications minister Jorge Rodriguez saying that the “media show” had perhaps been orchestrated to provoke an international uproar.
But he acknowledged that police officers had taken part in the arrest and said they would be disciplined.
“We want to inform the people of Venezuela that the officials who took that upon themselves are being dismissed,” Mr Rodriguez said on state TV.
At the rally after the incident, Mr Guaido told The Associated Press that the SEBIN agents informed him they were carrying out orders from above when they arrested him.
“We are survivors,” he told the crowd of a few hundred waving Venezuelan flags.
Mr Guaido has been leading an increasingly tense stand-off with Mr Maduro seeking to oust him from power, winning the support of some powerful international allies like US Secretary of State Mike Pompeo, who spoke to him by phone shortly after the 35-year-old assumed the presidency of the opposition-controlled National Assembly.
At a rally on Friday he said he was prepared to take over as Venezuela’s interim president and call for new elections, a move the US and regional governments support.
But for such a strategy to succeed, he said Venezuelans must take to the streets to express their discontent with Mr Maduro’s wrecking of what was once Latin America’s wealthiest nation.
To that end, he called for nationwide demonstrations on January 23 to coincide with the anniversary of the 1958 ousting of military dictator Marcos Perez Jimenez.