Mexican investigators are in the Gulf Coast state of Veracruz to interview several top officials about the recent killing of a photojournalist, an activist and three other women in the nation's capital.

Mexico City prosecutors say they have requested statements from the current and former Veracruz public security secretaries and the head of a state commission responsible for protecting journalists.

The commission says in a separate statement that its chief met with investigators Tuesday. No date was given for the other two officials to testify. Veracruz's governor has also been interviewed.

Ruben Espinosa was a photographer who fled to Mexico City after receiving threats. His friend and activist Nadia Vera was an outspoken critic of the Veracruz government.

Both were found dead last month along with the three other victims.