CARACAS -- Venezuela's Interior and Justice Minister Gustavo Gonzalez said Wednesday the murder of a right-wing opposition leader is the result of disputes among criminal gangs.

"This case is closed. The murder was to settle scores between bandits and gangsters," said Gonzalez.

The minister said several suspects have been identified, including Gilberto Hernandez Malony, the head of a criminal gang considered the mastermind behind the murder of Luis Manuel Diaz, the leader of the Democratic Action (AD) party in the central state of Guarico.

Diaz was shot dead on Nov. 25 after a campaign rally in the lead up to legislative elections on Sunday. Malony was suspected to have provided the weapon.

Authorities said the attack had "all the markings of rivalry between criminal gangs."

Three suspects, William Mendez Quiaro, Jose Enrique Abad and Ronald Hember Hernandez, were arrested on Nov. 30, and one testified to his involvement in the killing.

The minister showed a video in which Abad admits the killing resulted from a personal issue between Malony and "La Crema", Diaz's nickname.

According to Abad, the shooters "were given the order not to shoot Diaz while he was on the stage because the problem that we have is with him and no one else."

Following the incident, the Venezuelan government came under fire from many international organizations.

Hours after the murder, head of the Organization of the American States (OAS) Luis Almagro called for the suspension of the parliamentary elections, Venezuelan TV network Telesur reported.