For months, US spies had been monitoring Venezuelan President Nicolas Maduro’s every move.

A small team, including one source within the Venezuelan government, had been observing where the 63-year-old slept, what he ate, what he wore and even, according to top military officials, “his pets”.

Then, in early December, a planned mission dubbed “Operation Absolute Resolve” was finalised. It was the result of months of meticulous planning and rehearsals, which even included elite US troops creating an exact full-size replica of Maduro’s Caracas safe house to practise their entry routes.

The plan – which amounted to an extraordinary US military intervention in Latin America not seen since the Cold War – was closely guarded. Congress was not informed or consulted ahead of time. With the precise details set, top military officials simply had to wait for the optimal conditions to launch.

They wanted to maximise the element of surprise, officials said on Saturday. There was a false start four days earlier when US President Donald Trump gave approval, but they opted to wait for better weather and less cloud cover.

“Over the weeks through Christmas and New Year, the men and women of the United States military sat ready, patiently waiting for the right triggers to be met and the president to order us into action,” General Dan Caine, the nation’s highest-ranking military officer, told a news conference on Saturday morning.

Trump did not follow the mission from the White House situation room. Instead, he was surrounded by his advisers at his Mar-a-Lago club in Palm Beach, Florida, where he watched a live stream of the operation flanked by CIA Director John Ratcliffe and US Secretary of State Marco Rubio.

“It was an incredible thing to see,” Trump said on Saturday. “If you would have seen what happened, I mean, I watched it literally like I was watching a television show. And if you would’ve seen the speed, the violence… it’s just, it was an amazing thing, an amazing job that these people did.”

In recent months, thousands of US troops have deployed to the region, joining an aircraft carrier and dozens of warships in the largest military build-up in decades as Trump has accused Maduro of drug-trafficking and narco-terrorism, and blown up dozens of small boats accused of ferrying drugs through the region.

But the first signs of Operation Absolute Resolve were in the skies. More than 150 aircraft – including bombers, fighter jets and reconnaissance planes – were ultimately deployed through the course of the night, according to US officials.

“It was very complex, extremely complex, the whole manoeuvre, the landings, the number of aircraft,” Trump told Fox News. “We had a fighter jet for every possible situation.”

Loud explosions were heard in Caracas at about 02:00 local time (06:00 GMT), and plumes of smoke were seen rising over the city. “I heard a huge sound, a loud bang,” reporter Ana Vanessa Herrero told the BBC. “It moved all the windows. Immediately after I saw a huge cloud of smoke that almost blocked the entire view.”

She added: “Planes and helicopters were flying all over the city.”

Soon, videos showing numerous aircraft in the skies – and others showing the apparent aftermath of explosions – began to circulate widely on social media. One showed a convoy of helicopters flying at low altitude over Caracas as smoke rose from apparent detonations.

“We woke up at around 01:55 to the roar of explosions and the hum of planes flying over Caracas,” one witness, Daniela, told the BBC. “Everything was plunged into absolute darkness, illuminated only by the flashes of nearby detonations.”

She added: “Neighbours were messaging in the condominium group chat, all confused and unaware of what was happening [and] frightened by the blasts.”

BBC Verify has examined a number of videos showing explosions, fire and smoke in locations around Caracas to identify exactly which sites were targeted.

So far, it has confirmed five locations including Generalissimo Francisco de Miranda Air Base, an airfield known as La Carlota and Port La Guaira, Caracas’ main conduit to the Caribbean Sea.

“The lights of Caracas were largely turned off due to a certain expertise that we have,” he said. “It was dark and it was deadly.”

As strikes rang out around Caracas, US forces made their way into the city. They included members of the elite Delta Force, the US military’s top special mission unit, sources told the BBC’s US news partner CBS. They were heavily armed – and carried a blowtorch in case they had to cut through the metal doors of Maduro’s safe house.

The troops arrived at Maduro’s location shortly after the strikes began at 02:01 local time, according to Gen Caine. Trump described the safe house as a military “fortress” in the heart of Caracas, saying: “They were in a ready position waiting for us. They knew we were coming.”

The troops took fire when they arrived, and one of the US helicopters was hit but was still able to fly. “The apprehension force descended into Maduro’s compound and moved with speed, precision and discipline,” Gen Caine said.

“They just broke in, and they broke into places that were not really able to be broken into, you know, steel doors that were put there for just this reason,” Trump remarked.

It was only as the operation – which also saw Maduro’s wife, Cilia Flores, seized – was unfolding that Rubio began notifying lawmakers about the action, a decision which has since prompted anger from some in the US Congress.

“Let me be clear: Nicolas Maduro is an illegitimate dictator. But launching military action without congressional authorisation and without a credible plan for what comes next is reckless,” said top Democrat Chuck Schumer, the party’s leader in the Senate.

Briefing Congress ahead of time would have endangered the mission, Rubio told reporters during the news conference on Saturday. “Congress has a tendency to leak,” Trump added. “This would not be good.”

In Maduro’s compound, as elite US troops flooded in, Trump said the Venezuelan president – who has reportedly increased his reliance on Cuban bodyguards in recent months – attempted to flee to a safe room.

“He was trying to get to a safe place, which wasn’t safe, because we would have had the door blown up in about 47 seconds,” Trump said.

“He made it to the door. He was unable to close it. He got bum rushed so fast that he didn’t get into that [room].”

When asked if the US could have killed Maduro, an authoritarian leader who took over the presidency in 2013, if he had resisted arrest, Trump said: “It could have happened.”

On the US side, “a couple of guys were hit”, he said, but no US service members were killed.

In a statement on Sunday, Venezuelan Defence Minister Vladimir Padrino said a “large part” of Maduro’s security team and “soldiers and innocent civilians” were killed in the US operation.

The US had previously offered a $50m (£37m) reward for information leading to Maduro’s arrest. But by 04:20 local time on Saturday, helicopters were leaving Venezuelan territory with Maduro and his wife on board, in custody of the US Department of Justice and en route ultimately to New York, where they are expected to face criminal charges.

Almost exactly an hour later Trump announced the news of his capture to the world. “Maduro and his wife will soon face the full might of American justice,” he said.