Five days after the US seized its former president Nicolás Maduro, Venezuela has announced that it is releasing an “important number” of detainees in what the congressional president characterised as a gesture to “consolidate peace”.

It is still unclear how many people are being freed. Human rights organisations working in the country estimate that Venezuela holds between 800 and 1,000 political prisoners, most of them detained for taking part in protests after the 2024 election, widely believed to have been stolen by Maduro.

The congressional president Jorge Rodríguez – the brother of the acting president Delcy Rodríguez – said the move was a “unilateral gesture to reaffirm our unbreakable decision to consolidate peace in the republic and peaceful coexistence among all”.

Spain’s foreign ministry confirmed the release of “five Spanish nationals, one of them a citizen with dual nationality, who are preparing to travel to Spain with assistance from our embassy in Caracas”.

“Spain, which maintains fraternal relations with the Venezuelan people, views this decision as a positive step in the new phase Venezuela is entering,” the statement added.

Before the announcement, estimates suggested there were more than 40 foreign nationals detained in Venezuela, including about 20 Spaniards and five US citizens detained in Venezuela, including the traveller James Luckey-Lange, 28, who disappeared in December and was being held at military counterintelligence headquarters in Caracas.

On Tuesday, Donald Trump said Venezuela had “a torture chamber in the middle of Caracas that they’re closing up”, without elaborating. In recent days, speculation has centred on the Helicoide de la Roca Tarpeya – an iconic structure inaugurated in 1956 as an avant garde shopping centre and later turned into a prison and torture site under Chavismo – though there has been no confirmation.

El Helicoide de la Roca Tarpeya in Caracas, Venezuela. Photograph: Jesús Vargas/Getty Images

The announcement of the detainees’ release is being treated with caution. In the days leading up to the US operation, the regime said it would release 187 people – 99 on Christmas Day and 88 on New Year’s Day – but organisations were only able to independently verify the release of a portion of that total.

Alfredo Romero, the head of Foro Penal, an NGO that estimates there are still 806 political prisoners in Venezuela, posted a video saying: “We have good news that you all already know – it’s now official, and we have high expectations for the release of all political prisoners.”

Romero said he hoped this would be “a real transformation, a process of national reconciliation and pacification, and not a simple gesture … or a fiction in which some people are released only for others to be jailed. We hope this truly marks the beginning of the dismantling of Venezuela’s repressive system,” he added.

The NGO Justicia, Encuentro y Perdón (Justice, Meeting and Forgiveness), which also monitors political detentions and estimated that there were 1,011 political prisoners, posted that it welcomed the announcement but was still waiting for the releases to be “effective, immediate and verifiable”.

“It is essential to reiterate that freedom is not a benefit or a concession granted by those in power: freedom is a fundamental human right. No one should be deprived of it for legitimately exercising rights such as freedom of expression, political participation or the defence of human rights,” the organisation wrote.

In addition to demanding the release of “all” political prisoners, the NGO stressed that any release must be “full, immediate and without conditions” – a reference to the fact that many people freed in recent months were granted only conditional liberty, subject to precautionary measures such as travel bans, mandatory court appearances and restrictions on speaking to the media about their cases.

The NGO Comité por la Libertad de los Presos Políticos (Committee for the Freedom of Political Prisoners) posted that, so far, the regime has not provided full information. “Opacity and discretion continue to prevail in the handling of these releases, increasing the anxiety, anguish and uncertainty of families and political prisoners,” it said.

At the press conference announcing the decision, Rodríguez said: “In the next few minutes you will learn the nature of the people who are receiving the benefit of release.

“In order to contribute and collaborate in the effort that all of us must make for national unity and peaceful coexistence, the Bolivarian government, together with the institutions of the state, has decided to free an important number of Venezuelan and foreign individuals, and these release processes are taking place from this very moment.

“Consider this gesture by the Bolivarian government, with its broad intention of seeking peace, as the contribution that all of us must make so that our republic can continue its life in peace and in pursuit of prosperity,” he added.