The Mexican governor of Chihuahua said Wednesday she was "being persecuted" by the country's ruling party over the case of two U.S. officials who died in April during an unauthorized drug raid in her state.

Maria Eugenia Campos, from the opposition National Action Party, appeared for questioning at the Mexican General Prosecutors office in Mexico City regarding the April 19 incident.

The two Americans killed in the crash were employees of the Central Intelligence Agency, multiple people familiar with the matter told CBS News. The CIA declined to comment.

Outside the prosecutors office, Campos said she was being "persecuted with the entire weight of the state apparatus" while politicians from the ruling Morena party have "absolute impunity."

In the April incident, two CIA agents died in a car crash while accompanying soldiers and state prosecutors in a raid of a drug lab in Chihuahua.

Two Mexican investigators also were killed in the crash. In a news release, the state attorney general's office identified the two Mexican casualties as first commander of the state investigation agency Pedro Román Oseguera Cervantes and officer Manuel Genaro Méndez Montes.

President Claudia Sheinbaum ordered an investigation into the operation, saying it may have violated national security laws preventing unauthorized foreign agents from operating inside Mexico.

Anti-drug operations are the sole responsibility of the federal government, Sheinbaum said, noting the CIA agents hadn't announced their activities in accordance with U.S.-Mexico security agreements.

A statement from Mexico's Ministry of Security said one U.S. agent entered Mexico as a visitor while the other entered with a diplomatic passport.

"None had formal accreditation to participate in operational activities in national territory," the security ministry said.

At the end of April, the U.S. Justice Department requested the arrest and extradition of 10 politicians from the ruling party, including Sinaloa Gov. Ruben Rocha Moya, who they accused of protecting the cartel of the same name.

U.S. Ambassador Ronald Johnson expressed his condolences on social media after the incident but he and other officials provided few details about it.

"We honor their dedication and tireless efforts to confront one of the greatest challenges of our time," Johnson said. "This tragedy is a solemn reminder of the risks faced by those Mexican and U.S. officials who are dedicated to protecting our communities."