The Institutional Revolutionary Party, or PRI, candidate for mayor of Apaxtla de Castrejon, a town in the southern Mexican state of Guerrero, was kidnapped by three gunmen who showed up at his house, the party said.

Marcelo Avila, who was hoping to become the mayor of the town of about 7,000 people, was abducted on Monday afternoon, the PRI, which is in the opposition in Guerrero, said in a statement.

At least three gunmen pulled the mayoral candidate from his house in Apaxtla and his whereabouts is unknown, the PRI's State Administrative Committee said.

Avila's kidnapping should be investigated, the PRI said, adding that Guerrero, whose governor is Angel Aguirre, of the leftist Party of the Democratic Revolution, or PRD, was mired in a climate of violence ahead of Sunday's general elections.

At least 15 PRI candidates have received threats in the state's conflict zones and there are "candidates who have not campaigned" because of this, the PRI's leader in Guerrero, Cuauhtemoc Salgado, said in a press conference in Chilpancingo, the state capital.

"They have received messages on their cell phones and in calls," the state party leader said, without revealing if he suspected who was behind the threats.

"We have a critical situation, there is psychosis among the citizenry," Salgado said.

Avila is among the candidates who got threats, according to Salgado, who would not reveal the names of the other 14 for "security" reasons.

The kidnappers "have not contacted the family" of the mayoral candidate, Salgado said.

Apaxtla is in an area of Guerrero where gunmen working for drug cartels have staged a number of attacks.

The state's northern and Tierra Caliente regions have been especially affected by drug-related violence.

Rafael Ariza, a PRD politician, was abducted last week in the city of Coyuca de Benitez and the kidnappers have demanded the payment of ransom.

Ariza served as an adviser to Javier Bataz, who is running for mayor of Coyuca de Benitez.

Gov. Aguirre launched a security operation last year with the support of the federal government to step up security in areas frequented by foreign and domestic tourists, such as the Pacific resort city of Acapulco.

"Operation Safe Guerrero" was launched on Oct. 6, 2011, in an effort to reduce the soaring crime rate in the state. EFE