Miguel Angel Luna, a Mexican congressional candidate and former mayor of Valle de Chalco, has become the eighth politician to be murdered before the upcoming midterm elections, which take place this Sunday, as reported by Telesur.

Luna was shot on Tuesday in a town bordering Mexico City and died shortly afterward at a hospital.

According to a statement provided by his Democratic Revolution Party, the murdered candidate was attacked by armed men at his campaign offices. An assistant was also wounded in the incident.

“We condemn the attack against Miguel Angel Luna and we demand that the crime be solved as soon as possible,” read the PRD statement.

Aside from the political murders, Mexican news outlets Sin Embargo and El Universal have reported that 42 electoral candidates across Mexico have been violently attacked.

The upcoming midterm elections have been awash in political violence.

According to an Associated Press piece, the state electoral institute has reported that in Guerrero more than 116,000 ballots were burned by an armed group who broke into electoral offices in the city of Tlapa late on Monday. Similar ballot burnings and thefts have occurred in Oaxaca state.

Radical groups and unionized teachers that oppose a 2013 education reform, which requires competitive testing for teachers, have said that they intend to block Sunday's voting for the lower house of congress, nine governorships, as well as hundreds of mayorships.

​On Monday a coalition of civil society organizations led a so-called “march for peace” in Mexico City.

As reported by Telesur, Jose Antonio Ortega Sanchez, the president of the Citizen Council for the Justice and Security, explained to local media that “there are instances of risk and danger, and there may be problems, but I hope that there are none and that the majority of Mexicans head to the voting stating to cast their vote.”