The United Nations human rights chief Michelle Bachelet has called for an independent investigation into alleged excessive use of force by Venezuelan security forces, citing reports of 26 people killed and more than 350 detained in protests this week.

"I am extremely concerned that the situation in Venezuela may rapidly spiral out of control with catastrophic consequences", Ms Bachelet, a former president of Chile, said in a statement.

She urged political leaders to hold talks to defuse the situation after opposition leader Juan Guaido declared himself interim president.

We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences

As the death toll from days of street protests rose to 26, a defiant President Nicolas Maduro announced the closure of Venezuela's embassy and consulates in the United States, a day after President Donald Trump's administration declared his regime "illegitimate."

The oil-rich but economically devastated country was plunged into uncertainty on Wednesday when Mr Guaido, the 35-year-old head of the National Assembly, proclaimed himself "acting president" - earning swift endorsement from Washington and a dozen regional powers including Brazil, Argentina and Colombia.

Mr Maduro's re-election last year was contested by the opposition, and criticised internationally - but the socialist leader has until now retained the loyalty of the powerful military, whose response was being keenly watched.

Juan Guaido (L) declared himself interim president but the military remains loyal to Nicolas Maduro

Flanked by military top brass, Defence Minister Vladimir Padrino, himself a general, declared the 56-year-old Maduro "the legitimate president" - and vowed to defend his authority against an attempted "coup d'etat".

Following Mr Padrino's lead, eight generals in turn reiterated their "absolute loyalty and subordination" to the socialist leader in messages carried on state television.

And the Supreme Court - made up of regime loyalists - doubled down by reaffirming its allegiance to Mr Maduro's "legitimate authority."

In a Skype interview with Univision, Mr Guaido said he did not rule out including Mr Maduro in an amnesty he is offering for military and civilian officials who lead a transition in Venezuela.

But he said such an option would have to be evaluated because, he said, Mr Maduro is responsible for the death of protesters. 

Read more:
UN urges investigation into use of force in Venezuela
Venezuela's week in turmoil
Who is Venezuela's self-appointed interim president?
In pictures: Crisis in Venezuela

US Secretary of State Mike Pompeo kept up the pressure on Mr Maduro, as the United States called for an emergency UN Security Council meeting on the crisis.

"The time for debate is done. The regime of former president Nicolas Maduro is illegitimate," Mr Pompeo said in a speech to the Organization of American States, warning him against the use of force towards demonstrators.

Mr Maduro on Wednesday issued US diplomats a 72-hour deadline to leave the country, and yesterday said he was recalling all Venezuelan diplomats from the United States.

The US State Department meanwhile ordered its non-emergency staff to leave Venezuela but refused to comply with a full expulsion, saying it would maintain diplomatic ties with "the government of interim President Guaido."

Outside South America, the United States has been joined by Canada and Britain in recognising Mr Guaido as Venezuela's interim leader, while France has also rejected Mr Maduro's legitimacy.

But both Russia and China and have thrown their weight behind the embattled Mr Maduro.

Russian President Vladimir Putin called Maduro to express support, charging that the "crisis has been provoked from the outside."

China, Venezuela's main creditor, opposed "interference in Venezuelan affairs by external forces."

Mr Maduro has retained the support of Mexico, Cuba and Bolivia, all led by leftist governments.

He has presided over a deepening economic crisis that has left the country facing shortages of basic necessities such as food and medicine.

Some 2.3 million people have fled the country since 2015, according to the United Nations. Inflation is forecast to hit 10 million% this year.

Mr Guaido's bold move capped three days of high tension that began on Monday when a group of soldiers took over a command post in the capital Caracas and rose up against Mr Maduro.

That uprising was quickly quashed and officials said 27 people were arrested but it set off a wave of smaller protests that were met by security forces using tear gas and rubber bullets.

Wednesday then saw the first mass street protests in Venezuela since a crackdown on anti-government protests between April and July 2017 claimed the lives of 125 people.

Leading figures around the world have appealed for calm to avoid a repeat of the bloodshed - as a Caracas-based NGO, the Social Conflict Observatory, said 26 people had been killed since this week's protests began four days ago.

Speaking at the World Youth Day in Panama, Pope Francis's spokesman said he was "praying for the victims and for all the people of Venezuela."