Queues built up at the border between Venezuela and Brazil following the order to close it
Venezuelan President Nicolás Maduro has announced the closure of the border with Brazil as a row over foreign humanitarian aid continues.
The embattled leftist leader went on TV to say that he was also considering shutting the border with Colombia to stop the opposition bringing in relief.
He denies any crisis and calls the aid delivery plans a US-orchestrated show.
Opposition leader Juan Guaidó is leading a convoy from the capital, Caracas, to the Colombian border.
Later on Friday, a huge concert will be held on the Colombian side of the border to raise money for Venezuela.
At the same time, Mr Maduro’s government will hold its own event, reportedly just some 300 metres away.
Mr Guaidó declared himself interim leader during anti-government protests last month and is recognised by dozens of foreign states, including the US and most Latin American countries.
Scuffles broke out and tear gas was fired when the convoy of buses and cars was briefly stopped by security forces on a road near Mariara, west of Caracas, but they later moved on.
Meanwhile, after Mr Maduro’s announcement that the border would be closed indefinitely on Thursday night, many Venezuelans rushed across the frontier to the Brazilian city of Pacaraima to stock up on supplies, Brazilian news portal G1 reported.
The crossing usually closes at night and would normally have opened at 08:00 local time (12:00 GMT) on Friday.
Opposition figures scuffled with national guardsmen on the road taken by the convoy
Mr Guaidó and his allies hope to collect food and medicine in defiance of President Maduro.
The Venezuelan military has so far managed to block shipments of US aid from coming across the border with Colombia.
Despite denying there is any humanitarian crisis, Mr Maduro announced this week that 300 tonnes of aid would be shipped to Venezuela from its ally Russia.
How the story unfolded14 April 2013
Nicolás Maduro is narrowly elected president of Venezuela after the death of long-serving socialist leader Hugo Chavez. The vote is marred by claims of fraud by the opposition.
18 February 2014
A wave of protests against Mr Maduro leads to the arrest of opposition leader Leopoldo Lopez, who remains under house arrest.
29 March 2017
Venezuela’s Supreme Court says it is taking control of the National Assembly, prompting months of anti-government protests that leave 100 dead. The Supreme Court reverses its decision.
17 July 2017
More than seven million Venezuelans vote in an opposition-organised referendum against Mr Maduro’s plans to create a new body with the power to control the National Assembly.
20 May 2018
Mr Maduro wins snap election. The two leading opposition candidates reject the results, saying the election was marred by vote-rigging.
8 November 2018
The UN announces that the number of refugees and migrants who have left Venezuela has passed three million. Venezuela’s economy is tanking, creating widespread food and medicine shortages.
10 January 2019
Mr Maduro is inaugurated as president. The little-known new leader of the National Assembly, Juan Guaidó, calls the president a “usurper”.
21 January 2019
As Venezuela’s economy continues to fail, a Caracas based charity says it has recorded at least 107 episodes of looting and several deaths across the country.
23 January 2019
Citing emergency powers, Mr Guaidó declares Mr Maduro’s leadership illegitimate and claims the presidency. He is recognised by the US and several Latin American countries, creating two rival claims to the office.
7 February 2019
Humanitarian aid arrives at the Colombian border with Venezuela, ready to enter the country, but Mr Maduro instructs the army to block the roads with oil tankers.
More than three million Venezuelans have fled in recent years as the country grapples with hyperinflation and shortages of essentials like food and medicine, the UN says.
Mr Maduro, in power since 2013, has been criticised at home and abroad for his handling of the economy.
Is support for Guaidó growing?
Venezuela’s military has so far resisted calls to abandon President Maduro and support his rival.
However, on Thursday former military intelligence chief Hugo Carvajal recognised the opposition leader as “president in charge”. In a video address posted online he issued a stinging rebuke to Mr Maduro.
“You have killed hundreds of young people in the streets for trying to claim the rights you stole – this without even counting the dead for lack of medicines and security,” he said.
Mr Carvajal, a congressman, called on the military to break with the president and to allow humanitarian aid in.
In another development, Mr Guaidó’s aides in Washington said 11 Venezuelan diplomats based in the US had defected and declared their support for him.
Why is the Brazilian border being shut?
Flanked by Defence Minister Vladimir Padrino Lopez and other top military commanders, Mr Maduro announced that the border with Brazil would be closed “completely and absolutely” until further notice.
The president also added: “I don’t want to take any decision of this type but I am evaluating it, a total closure of the border with Colombia.”
He says the delivery of aid is part of a US-led attempt to depose his government and seize Venezuela’s oil reserves.
The right-wing Brazilian government of President Jair Bolsonaro is among those that recognise Mr Guaidó as Venezuela’s legitimate leader, pending elections.
Presidential spokesman Gen Otávio Régo Barros said on Tuesday that, in co-ordination with the US, food and medicine would be available in the border town of Pacaraima to be collected by “the government of acting President Juan Guaidó in Venezuelan trucks driven by Venezuelans”.
“Brazil is taking part in this important international initiative to support the Guaidó government and the Venezuelan people,” he said.
Mr Guaidó has said 600,000 volunteers have already signed up to help carry aid into the country on Saturday.
Venezuela earlier closed its sea and air border with Curacao, a Dutch Caribbean island off Venezuela’s north coast which is planning to host US aid.
Where is Guaidó’s convoy going?
It is expected to travel some 800-900km (500-560 miles) to the Colombian border where aid is being stockpiled on the Colombian side, in the city of Cúcuta.
“Confirmed – it’s rolling,” a spokesman for Mr Guaidó’s convoy told AFP news agency on Thursday after he left Caracas by car.
“We know that the regime is going to put all obstacles to prevent us from reaching the border, but nothing is stopping us, we are going to continue,” opposition MP Yanet Fermin told the news agency.
Meanwhile, the Venezuelan government announced it would deliver 20,600 of its own food boxes to the Colombian border area.
A video posted on Twitter by Food Minister Luis Medina Ramírez showed cargo lorries.
Battle of the bands?
British entrepreneur Sir Richard Branson has organised a huge benefit concert for Friday near the Tienditas Bridge crossing, on the Colombian side of the border at Cúcuta, to raise money for Venezuela.
Venezuela Aid Live, he says, was organised at the request of Mr Guaidó and another opposition leader, Leopoldo López.
The Branson concert is on the Colombian side of Tienditas Bridge…
. and a Venezuelan government stage has gone up just a few hundred metres away
About 250,000 people are expected at a gig which organisers hope will raise about $100m (£77m) to buy food and medicine for Venezuelans, Reuters news agency reports.
Not to be outdone, the Venezuelan government has erected a stage on its side of the crossing.