Helicopter goes down in mountainous area outside Caracas en route to military exercises led by President Maduro.

Seven Venezuelan military officers were killed on Saturday when their helicopter crashed outside Caracas, President Nicolas Maduro said.

The helicopter had left the Venezuelan capital heading to San Carlos in the country’s northwest when it went down in a mountainous area of the El Hatillo municipality, the defence ministry said in a statement.

On Twitter, Maduro mourned the loss of “seven worthy officers of the country”, including two majors, three captains and two lieutenant colonels.

The defence ministry said an investigation into the cause of the crash was under way.

Maduro was in San Carlos on Saturday, leading military exercises with top brass and more than 5,000 troops.

It was a show of strength against opposition leader Juan Guaido, whose attempt to launch a military uprising earlier in the week had failed.

Guaido, the president of the country’s National Assembly, was continuing his efforts to persuade the armed forces to abandon Maduro.

The opposition leader made a fresh bid on Saturday to rally the country’s armed forces behind him, calling on his supporters to march to military bases and barracks.

But there was a small turnout for the marches, with participants in the hundreds, not the thousands. This was another setback for Guaido following a failed military uprising earlier in the week.

Maduro on Saturday instructed the military “to be ready to defend the homeland with weapons in your hands if one day the US empire dares to touch this territory, this sacred earth”.

Underscoring the continued military support for his government, Maduro delivered his televised address from a base in the northwestern Cojedes state, where he appeared alongside defence minister, Vladimir Padrino, and in the presence of more than 5,000 troops.

The United States has refused to take the threat of military action off the table in its push to oust Maduro — although it so far has limited its campaign to ramping up sanctions.

Guaido’s cause gained renewed support on Saturday from US Secretary of State Mike Pompeo, who issued a video address to the Venezuelan people, telling them: “The time for transition is now.”

“You can hold your institutions, your military and their leaders to the highest standards and demand a return to democracy,” Pompeo said in the message. “The United States stands firmly with you in your quest.”

Guaido, 35, has branded Maduro a usurper over his re-election last year, and in January declared himself acting president, plunging Venezuela into a political crisis that has deepened its already grave economic woes.

But Maduro has held firm, bolstered by the continued support of the powerful armed forces.

“I told the generals and admirals yesterday: loyalty, I want an active loyalty… I trust you, but keep your eyes open, a handful of traitors cannot tarnish the honour, the unity, the cohesion and the image of the armed forces,” the president said, in his speech from the military base.