Venezuela crisis: How the political situation escalated
In Venezuela, the government of President Nicolás Maduro and the opposition are engaged in a bitter power struggle.
The South American country has been caught in a downward spiral for years with growing political discontent further fuelled by skyrocketing hyperinflation, power cuts and shortages of food and medicine.
About four million Venezuelans have left the country in recent years.
But what exactly is behind the crisis rocking Venezuela?
Who's the president?
This would be an unusual question to ask in most countries, but in Venezuela many want to know exactly that as the government accused opposition leader Juan Guaidó of trying to topple President Maduro.
The accusation came after Mr Guaidó - surrounded by a group of men in uniforms - called on the military to switch sides on 30 April.
Tension had been mounting ever since 23 January, when Mr Guaidó declared himself acting president and said he would assume the powers of the executive branch from there onwards.
The move was a direct challenge to the power of President Maduro, who had been sworn in to a second six-year term in office just two weeks previously.
Not surprisingly, President Maduro did not take kindly to his rival's move, which he condemned as a ploy by the US to oust him.
He also said that he was the constitutional president and would remain so.
Why is the presidency disputed?
Nicolás Maduro was first elected in April 2013 after the death of his socialist mentor and predecessor in office, Hugo Chávez. At the time, he won by just 1.6 percentage points.
During his first term, the economy went into freefall and many Venezuelans blame him and his socialist government for the country's decline.
Mr Maduro was re-elected to a second six-year term in May 2018 in highly controversial elections, which most opposition parties boycotted.
Many candidates had been barred from running while others had been jailed or fled the country for fear of being imprisoned, and the opposition parties argued that the poll would be neither free nor fair.
Mr Maduro's re-election was not recognised by Venezuela's opposition-controlled National Assembly.
Why is it all coming to a head now?
After being re-elected, Mr Maduro announced he would serve out his remaining first term and only then be sworn in for a second term on 10 January.
It was following his swearing-in ceremony that the opposition to his government was given a fresh boost. The National Assembly argues that because the election was not fair, Mr Maduro is a "usurper" and the presidency is vacant.
This is a line that is being pushed in particular by the new president of the National Assembly, 35-year-old Juan Guaidó.
Citing articles 233 and 333 of Venezuela's constitution, the legislature says that in such cases, the head of the National Assembly takes over as acting president.
That is why Mr Guaidó declared himself acting president on 23 January. Since then, he has been organising mass protests and calling on the military to switch allegiance.
What has the reaction been?
More than 50 countries have recognised Mr Guaidó as the legitimate president, among them the US and many nations in Latin America.
But Russia and China among others have stood by President Maduro.
Within Venezuela, those opposed to the government celebrated Mr Guaidó's move, while government officials said they would defend the president against "imperialist threats".
While Mr Guaidó counts on the support of many international leaders, he does not have much power in practical terms.
The National Assembly was largely rendered powerless by the creation of the National Constituent Assembly in 2017, which is exclusively made up of government loyalists.
The National Assembly has continued to meet, but its decisions have been ignored by President Maduro in favour of those made by the National Constituent Assembly.
Who can break the impasse?
The security forces are seen as the key player in this crisis. So far, they have been loyal to Mr Maduro, who has rewarded them with frequent pay rises and put high-ranking military men in control of key posts and industries.
Mr Guaidó has promised all security forces personnel an amnesty if they break with President Maduro.
On 30 April, Mr Guaidó published a video on Twitter in which he again called on the military to switch sides. The footage showed him surrounded by a group of men in uniforms in a location near La Carlota air base.
He said he had the support of the military and announced the beginning of the "final phase" of his takeover of power. But Defence Minister Vladimir Padrino said all military bases remained under government control and were operating normally.
In May, representatives from the government and the opposition met in Norway for exploratory talks on how to resolve the crisis.
The talks were later moved to Barbados but, on 7 August, President Maduro ordered his representatives to pull out of the talks.
His decision came just days after the US had imposed sweeping sanctions on Venezuela, including a freeze on all Venezuelan government assets in the US and a bar on transactions with his government.
Mr Maduro called the move a "grave and brutal aggression" and said he would not negotiate with the opposition, which he attacked for backing the sanctions.
How did Venezuela get this bad?
Some of the problems go back a long time. However, it is President Maduro and his predecessor Chávez who are the target of much of the current anger.
Their socialist governments have been in power since 1999, taking over the country at a time when Venezuela had huge inequality.
But the socialist polices brought in which aimed to help the poor backfired. Take price controls, for example. They were introduced by President Chávez to make basic goods more affordable to the poor by capping the price of flour, cooking oil and toiletries.
But this meant that the few Venezuelan businesses producing these items no longer found it profitable to make them.
Critics also blame the foreign currency controls brought in by President Chávez in 2003 for a flourishing black market in dollars.
Since then, Venezuelans wanting to exchange bolivars for dollars have had to apply to a government-run currency agency. Only those deemed to have valid reasons to buy dollars, for example to import goods, have been allowed to change their bolivars at a fixed rate set by the government.
With many Venezuelans unable to freely buy dollars, they turned to the black market.
What are the biggest challenges?
Arguably the biggest problem facing Venezuelans in their day-to-day lives is hyperinflation. The annual inflation rate reached 1,300,000% in the 12 months to November 2018, according to a study by the National Assembly.
By the end of 2018, prices were doubling every 19 days on average. This has left many Venezuelans struggling to afford basic items such as food and toiletries.
The price of a cup of coffee in the capital Caracas doubled to 400 bolivars ($0.62; £0.50) in the space of just a week last December, according to Bloomberg news agency.
How have Venezuelans reacted?
According to United Nations figures, about four million Venezuelans have left the country since 2014 when the economic crisis started to bite.
However, Vice-President Delcy Rodríguez has disputed the figures, saying they are inflated by "enemy countries" trying to justify a military intervention.
The majority of those leaving have crossed into neighbouring Colombia, from where some move on to Ecuador, Peru and Chile. Others have gone south to Brazil.
The mass migration is one of the largest forced displacements in the western hemisphere.