Jose Remedios Aguirre was killed by gunmen in the town of Apaseo El Alto, according to officials in Guanajuato state.

Gunmen have shot dead a candidate in central Mexico ahead of a July election, marking the third murder of a politician within the country in the past week.

Jose Remedios Aguirre, a mayoral hopeful for the leftist Morena party in Guanajuato state, was killed in the town of Apaseo El Alto on Friday, the state prosecutors’ office said.

Ricardo Sheffield, a Morena candidate for governor in Guanajuato state, told Al Jazeera that the party resumed campaigning on Saturday “to honour Aguirre”.

He had previously suspended all campaigning in the state until officials could guarantee the safety of all its contenders, according to a report by the Associated Press news agency.

“It’s very unfortunate what we are living through, particularly in Guanajuato, which is the state this year with more violence than anywhere else in Mexico,” Sheffield said.

“Our governor sticks his head in the ground like an ostrich and ignores what is happening; people are being killed every single day.”

The office of incumbent Guanajuato Governor Miguel Marquez denounced Aguirre’s murder in a Twitter post on Friday, adding that a special investigation had been set up to investigate the killing.

Campaigning marred by violence

Aguirre’s murder followed the killing on Tuesday of a state assembly candidate for the ruling Institutional Revolutionary Party in Mexico’s western Guerrero state.

The killing took place four days after Morena’s mayoral candidate in the city of Tenango del Aire, in Mexico state, was murdered on May 4.

Scores of politicians have been killed in Mexico since September 2017, when campaigning for the country’s July 1 elections began.

The ballot will see voters elect a president on a six-year term, 500 members of the lower house Chamber of Deputies and 128 members of the upper house Senate.

Voters will also select local representatives.