Mexico City, June 3 (IANS): A Party of the Democratic Revolution (PRD) congressional candidate was killed in his campaign headquarters in Valle de Chalco, a city in Mexico state, and another candidate was wounded, Spanish news agency Efe reported on Wednesday citing state prosecutors.

Miguel Angel Luna was murdered on Tuesday by several unidentified individuals who entered his campaign headquarters and opened fire in an attack that Governor Eruviel Avila said was not linked to the elections that will be held next Sunday.

Luna was shot in the chest, the Mexico state attorney general's office said in a statement.

Tonatiuh Gutierrez, a candidate for councilman in Valle de Chalco, was wounded in the attack, the Party of the Democratic Revolution said.

Mexico state, which surrounds the federal district and forms part of the Mexico City metropolitan area, is the country's most populous state.

"After the attack, the wounded man was transported to Fernando Quiroz Hospital, of the Mexico state health service, where he arrived without any vital signs," the attorney general's office said.

Mexico is holding its midterm elections next Sunday, with 500 seats in Congress, nine governorships, including that of Guerrero and 1,532 local offices up for grabs.