Image copyright Michael Wimbish/US Southern Command Image caption Photo released by US Southern Command showing a Venezuelan SU-30 Flanker

The United States military has accused a Venezuelan fighter aircraft of endangering the crew of a US navy plane in international airspace.

The Venezuelan plane made an "unsafe approach" and "aggressively shadowed" the US reconnaissance aircraft over the Caribbean Sea, US Southern Command said on Sunday.

Venezuela said the US plane had entered Venezuelan airspace without permission.

Relations between the two countries have been tense for years.

The incident happened on Friday, the same day the US treasury department imposed sanctions on four members of Venezuela's military counterintelligence directorate (DGCIM) for their alleged role in the physical abuse and death of a Venezuelan navy captain, Rafael Acosta.

Capt Acosta's death, which a leaked forensic report suggests occurred after he was severely beaten, asphyxiated and given electric shocks while in DGCIM custody, caused an international outcry earlier this month.

What does the US say happened?

US Southern Command took the unusual step of not only releasing their description of the incident but also publishing video of the Russian-made jet on Twitter.

In a further tweet, US Southern Command said the action demonstrated "Russia's irresponsible military support to Maduro's illegitimate regime and underscores Maduro's recklessness & irresponsible behaviour, which undermines international rule of law and efforts to counter illicit trafficking".

The US is one of the more than 50 nations which does not recognise President Maduro and his government, arguing that the 2018 polls which saw him re-elected to a second term were neither free nor fair.

But Russia continues to support Mr Maduro and has in the past said it will do "everything required" to support him as Venezuela's "legitimate president".

Media playback is unsupported on your device Media caption Venezuela crisis: The four countries interested in the presidential battle

The reference to Russia's military support in the tweet posted by Southern Command shows their annoyance not just with the fact their plane was intercepted but also that it was a fighter aircraft developed by Russia's Sukhoi Aviation Corporation.

What does Venezuela say?

The Venezuelan armed forces' strategic operational command also took to Twitter [in Spanish] to reject the allegations made by the US military.

The US aircraft, it said, had entered Venezuelan airspace without complying with the protocols of the International Civil Aviation Organization, which "put the security of air traffic at risk".

It alleges the US aircraft acted "irresponsibly" by turning off its transponder to avoid being identified.

The Venezuelan military says two of its fighter jets intercepted the US plane and escorted it out of Venezuelan airspace.

What's the background?

This is the latest in a series of spats between the US and the Venezuelan military. Venezuela alleges that "more than US spy planes" have entered its airspace without permission so far this year.

The Venezuelan government accuses the US of being behind a plot to oust President Maduro.

The US has given its backing to the head of the National Assembly, Juan Guaidó, who in January 2019 declared himself president.

Mr Guaidó argues President Maduro is a "usurper" and that the presidency is therefore vacant, in which case the constitution calls for the head of the National Assembly to step in.

Last week, the LA Times reported that the US administration was planning to divert more than $40m (£32m) in humanitarian aid from Central America to Mr Guaidó to pay for, among other things, his team's salaries and airfares.

Representatives of the Venezuelan government and of the opposition are currently holding talks in Barbados in a way to solve Venezuela's political crisis but so far no details of what is being discussed have emerged.