Venezuela opposition leader Maria Corina Machado was freed on Thursday after a brief detention, her Vente Venezuela movement said on social media.

Machado was detained after an anti-government march in Caracas, her first public appearance in months, amid gunshots, the movement said, adding that during her detention she was forced to film several videos.

Earlier, her ally, former presidential candidate Edmundo Gonzalez, demanded she be freed immediately as government officials including Interior Minister Diosdado Cabello said her arrest was "an invention, a lie."

Vente Venezuela had said Machado was "violently intercepted" in eastern Caracas, and that the motorcycle caravan in which she was riding had been shot at.

The opposition are protesting around the country in an eleventh-hour effort to put pressure on Maduro.

Both the opposition and the ruling party claim to have won last year's presidential election.

The country's electoral authority and top court say Maduro, whose time in office has been marked by a deep economic and social crisis, won the July vote, though they have never published detailed tallies.

The government, who has accused the opposition of fomenting fascist plots against it, has said it will arrest Gonzalez should he return to the country and has detained prominent opposition members and activists in the lead-up to the inauguration.

Gonzalez, 75, has been on a tour of the Americas this week and met with U.S. President Joe Biden and president-elect Donald Trump's national security adviser.

The White House and U.S. State Department did not immediately respond to requests for comment on reports of Machado's arrest.

'Tomorrow they will finally bury themselves': Machado

Venezuela's Ministry of Information did not immediately respond to questions about Machado's whereabouts, while the attorney general said in a message to Reuters he would not be commenting.

"Whatever they do, tomorrow they will finally bury themselves," Machado said during the protest. "Let no one be in doubt, what they do tomorrow marks the end of the regime."

Machado's appearance marked her first public outing since August when she went into hiding at an unknown location.

Machado, 57, had urged protesters to peacefully flood the streets and repeatedly asked members of the police and military — who guarded polling stations during the election — to back Gonzalez's victory.

"I'm not afraid, I lost my fear a long time ago," said 70-year-old Neglis Payares, a retired central bank worker, as she gathered with other opposition supporters in western Caracas in the morning.

Reuters witnesses estimated some 7,000 people had gathered in Caracas by around 2:20 p.m. local time. In the days after the election, thousands also took to the streets.

Maduro, 62, has been in power since 2013. He has the vociferous support of leaders in the armed forces and the intelligence services, which are run by close allies of powerful Interior Minister Diosdado Cabello.

Security forces set up checkpoints around the country.

Gonzalez has repeatedly pledged to return to Venezuela but given no details about how. An arrest warrant was issued for him for alleged conspiracy, prompting his September flight to Spain.

Machado being investigated by attorney general

Machado is being investigated by the attorney general in at least two cases, but no warrant for her has been made public.

The government has detained several high-profile politicians and activists, including a former presidential candidate. This week, the attorney general's office said it had freed more than 1,500 of the 2,000 people, including teenagers, detained during post-election protests.

Venezuelans living abroad also held protests, including in Madrid, where Gonzalez's daughter Carolina Gonzalez spoke to hundreds of demonstrators.

"My dad sends a hug to all of you, glory to the brave people of Venezuela," she said, her voice breaking.