CHILPANCINGO (AFP) - The governor of the Mexican state where 43 students vanished following a confrontation with police resigned on Thursday, saying he was stepping down to assist the investigation into the disappearances.

Family and loved ones of the missing students had repeatedly called for Guerrero governor Angel Aguirre to go in the wake of the scandal which has triggered nationwide and international outrage.

"I have decided to take my leave from the state parliament," Aguirre told a news conference, saying he hoped his decision would create a "political climate which allows attention to these matters and their solution".

Mexican authorities have searched in vain for any trace of the trainee teachers who disappeared on Sept 26 in the city of Iguala.

On Wednesday tens of thousands marched through Mexico City and other cities to protest the disappearance of the students and failure to find them.

Mexico authorities have ordered the arrest of the mayor of Iguala, his wife and an aide, alleging they masterminded the attack which left six students dead and the 43 missing.

Aguirre did not specify how long he planned to take leave from his post, stating only that the regional parliament should choose an individual who "must lead this effort in the coming months".

The next gubernatorial elections for Guerrero state are scheduled for June 2015, meaning Aguirre could theoretically not return to office.

The student disappearances have shone a light on the murky relationships between corrupt officials, police and drug cartels in Mexico.

Authorities say local officials and police worked closely with the Guerreros Unidos drug cartel in the attack, which could prove to be one of the worst slaughters of Mexico's bloody eight-year drug war.

Authorities have found several mass graves in Iguala but say 28 sets of remains examined so far do not correspond to the students.