VENEZUELAN authorities have arrested six “terrorists and hired killers” over an alleged assassination attempt on President Nicolas Maduro using explosive-laden drones on Saturday.

Investigators searched a blackened apartment building on Sunday (local time) where witnesses described seeing a drone and then hearing a thunderous explosion in what President Nicolas Maduro called an assassination attempt by the embattled nation’s opposition.

Opposition leaders decried Mr Maduro for broadly singling out his political opponents for the attack without providing any evidence, and they warned that he may use it to further suppress those critical of his government at a time of a crippling economic and humanitarian crisis.

The government denounced the attack as an attempt to kill not only Mr Maduro but an entire rank of the government’s top leadership that was standing beside him on a platform to celebrate the National Guard’s 81st anniversary.

In a stern message on state television, Defence Minister Vladimir Padrino Lopez said anyone who attacks Venezuela “will be met with a forceful response.”

As is often the case in Venezuela, accounts of exactly what happened remained murky. Government officials offered few new details, saying only that the incident involved two drones, one of which crashed into an apartment building two blocks from where Mr Maduro was speaking.

Of the six arrested, Interior Minister Nestor Reverol said two had previously been detained in street protests.

Venezuela has been periodically rocked by demonstrations over shortages of food and medical supplies that officials claim incite violence.

Two witnesses who live in nearby apartment buildings say they saw a drone hovering over a residential street and then heard a forceful explosion.

Maerum Gonzalez said she ran in terror to her fifth-floor balcony and then heard a second explosion and saw smoke rising.

“It was so strong the building shook,” she said.

“I said, ‘Oh my God, what happened? It terrified me.”’

Another witness showed The Associated Press cellphone video of a drone hovering over the street and then crashing into a building.

The witness, who did not want to be identified for fear of reprisal, said he then saw the drone fall to the ground, setting off an explosion.

The witness said he saw police arrest a man purported to be piloting the drone.

Information Minister Jorge Rodriguez said the incident took place shortly after 5:30pm Saturday (local time) as Mr Maduro was delivering a televised speech to hundreds of soldiers. He and his wife, Cilia Flores, looked up at the sky and winced after hearing an explosion.

Visibly shaken, he later said in a televised broadcast that he saw a “flying device” that exploded. He at first thought it might be a pyrotechnics display.

Within seconds, Mr Maduro said he heard a second blast and pandemonium broke out. Bodyguards escorted him from the event, covering him in black shields, and TV footage showed uniformed soldiers break formation and scatter.

Mr Maduro, a deeply unpopular president who was recently elected to a new term in an internationally condemned vote, later gave an impassioned retelling of the event.

“This was an attempt to kill me,” he said.

Mr Maduro said the “far right” working in co-ordination with detractors in Bogota and Miami, including Colombian President Juan Manuel Santos, were responsible.

Colombia’s government has vehemently denied that Mr Santos had any participation in the drone attack.

The Broad Front opposition alliance accused the government of leaping to assumptions and of making “irresponsible” accusations castigating all the opposition without any proof.

“This confusing event could be used as an excuse to repress the constitutional rights of the people to continue protesting for the defence of their rights,” the group said.

Venezuela’s government routinely accuses opposition activists of plotting to attack and overthrow Maduro, the socialist successor to the late President Hugo Chavez.

Mr Maduro has steadily moved to concentrate power as the nation reels from soaring hyperinflation that the International Monetary Fund projects could top 1 million per cent by year’s end as the country’s crisis deepens.

Mr Maduro called on US President Donald Trump to hold the “terrorist group” accountable.

Mr Trump’s national security adviser John Bolton told Fox News Sunday that “if the government of Venezuela has hard information that they want to present to us that would show a potential violation of US criminal law, we’ll take a serious look at it.”

It was not the first time Mr Maduro’s government has come under attack. Amid deadly, near-daily protests last year, a rogue police officer flew a stolen helicopter over the capital and launched grenades at several government buildings.

Oscar Perez and several comrades were later killed in a gunbattle after over six months at large.

A little-known group calling itself Soldiers in T-shirts claimed responsibility for Saturday’s attack, saying it planned to fly two drones loaded with explosives at the president, but soldiers shot them down. The authenticity of the message could not be independently verified, and the organisation did not respond to a message from the AP.

“It was not successful today, but it is just a matter of time,” the group said in a tweet.

David Smilde, a senior fellow at the Washington Office on Latin America, said the incident did not appear to be staged for political gain.

The “amateurish” attack prompted embarrassing images of Mr Maduro cut off midsentence with droves of soldiers running in fear, making him appear vulnerable, Mr Smilde noted. Despite the optics, he said he suspected that Mr Maduro would nonetheless find a way to take advantage of it.

“He will use it to concentrate power,” Mr Smilde said.

“Whoever did this, he’ll use it to further restrict liberty and purge the government and armed forces.”

The event had been just one more of many Mr Maduro routinely holds with the military, a key faction of Venezuelan society whose loyalty he has clung to as he struggles with an economic crisis considered worse than the US Great Depression.

Mr Maduro said the incident had left him more convinced than ever that military supports him.

“That drone came after me,” he said.

“But there was a shield of love that always protects us. I’m sure I’ll live for many more years.”