Mexico City: As Mexico sees a rise in attacks ahead of general elections, a mayoral candidate has been shot dead at a campaign rally in Mexico's southern Guerrero state, reported Al Jazeera.

Alfredo Cabrera was murdered on Wednesday in the town of Coyuca de Benitez.

A video shared by local media showed a person approaching him at the campaign event and shooting him several times at point-blank range.

Cabrera's killing adds to the climbing death toll in the run-up to presidential, congressional and local polls scheduled to be held on June 2, as reported by Al Jazeera.

Earlier on Tuesday, the Mexican government said that at least 22 people running for local office had been murdered since last September.

A mayoral candidate in the central state of Morelos was murdered on Tuesday, while another one was shot and wounded in western Jalisco state, the authorities said.

Cabrera belonged to an opposition coalition backing Xochitl Galvez, a centre-right senator and businesswoman with Indigenous roots, who is currently polling second in the presidential race.

Guerrero Governor Evelyn Salgado condemned the "cowardly" murder, saying that she had asked the state prosecutor's office to bring "the full weight of the law against the person or persons responsible".

According to the prosecutor's office, the alleged attacker was killed at the scene.

Notably, the drug cartels have often carried out political assassination attempts in order to control local police or extort money from municipal governments, Al Jazeera reported.

In April, Mexico President Andres Manuel Lopez Obrador acknowledged that the cartels often seek to determine who will serve as mayor - either by running their own candidates or eliminating potential rivals.

"They make an agreement and say, 'this person is going to be mayor; we don't want anyone else to register to run', and anybody who does, well, they know [what to expect]," he said at the time.

Following these killings, the government have been prompted to provide bodyguards for about 250 candidates, while those running for municipal positions - the most endangered - are the last in line for security, reported Al Jazeera.

The Institutional Revolutionary Party (PRI), one of the opposition coalition parties, accused the government of having "not made even the slightest effort to guarantee the safety of the candidates".

Moreover, about 27,000 soldiers and National Guard members will be deployed to reinforce security during Sunday's elections, according to Al Jazeera.

(With Inputs From Agencies)