Venezuela chief prosecutor, Tarek Saab, said on Tuesday two high-ranking military officers were arrested for their alleged involvement in drone explosions during a speech by President Nicolas Maduro earlier in August.

The South American country’s government has accused opposition politicians and anti-Maduro activists abroad of scheming to assassinate the leftist leader with the drones, which were laden with explosives, during a military parade.

Fourteen people, including a lawmaker and several young men, have been arrested, while another 20 suspects remain at large, including in neighbouring Colombia and the United States, according to authorities.

Saab said Colonel Pedro Zambrano and General Alejandro Perezhad been presented in court on Monday.

Further details were not immediately available about the detainees.

The Information Ministry, which handles media inquiries on behalf of the government, did not respond to a request for comment.

Reuters was unable to contact the two officers.

The alleged involvement of military officials in the drone incident is notable in the convulsed oil-rich nation where the armed forces have long been powerbrokers.