The interior minister of Venezuela said Friday that 12 people were arrested for sabotaging the electric grid in the northwestern state of Zulia, claiming that the masterminds were in neighboring Colombia.

"We arrested 12 people and issued arrest warrants for nine others. Twenty-one people are under investigation," Nestor Reverol said during a joint appearance on state television with the minister of electric energy, Luis Motta Dominguez.

The suspects were involved since last year in sabotaging "all of the electric substations located in the municipality of Mara," in the state of Zulia, Reverol said.

On Friday morning, an explosion at a substation in Maracaibo, the capital of the state of Zulia, was reported, and the minister made his statement at the spot where another substation had allegedly been sabotaged.

"This is one of the substations that was sabotaged by criminal and unscrupulous groups working in collaboration with external actors in Colombia, where the masterminds of the electric sabotage taking place in Zulia are hiding. This is one of the 12 substations that has been sabotaged in 2018," he said.

Motta Dominguez told Globovision that he found it suspicious that opposition leader Maria Corina Machado had called on Venezuelans to "insurrect" in Zulia just a few hours before the substations exploded.

"It grabs my attention that a well-known opposition leader was here yesterday, calling on Venezuelans to insurrect and saying that the insurrection will begin in Zulia, and that the substations exploded that same night," he said.