The governor of Guerrero state, Angel Aguirre, said on Thursday it was time to put his duties on hold and let lawmakers decide who should take the role.
Aguirre, a member of the leftist Party of the Democratic Revolution and governor for the past three years, has faced relentless criticism since 43 students disappeared without trace in the town of Iguala. Six more were found dead.
The "leave of absence" was the only option available to the 58-year-old who, by law, is not able to resign.
The leader of Aguirre's Party of the Democratic Revolution (PRD), Carlos Navarette, repeated Aguirre's assertion that he was standing down to improve the political atmosphere amid an ongoing investigation into the deaths and disappearances.
"Let it be clear that Angel Aguirre, even though he's no longer in the job, will be ready to contribute to investigations to clear up the facts," said Navarette.
Police in Iguala are suspected of having been in league with local gangsters and to have acted at the behest of the town's mayor, Jose Luis Abarca, in events that led to the disappearances and killings. Arrest warrants have been issued for Abarca, his wife, and a local police chief.
As news of Aguirre's decision filtered out, rumors circulated on Twitter that the mayor had been detained in the coastal city of Veracruz.
Students sought donations
The students from the Rural Normal School of Ayotzinapa disappeared on September 26, when they had traveled to Iguala to solicit donations.
Prosecutors claim Abarca ordered police to confront the students, fearing they intended to disrupt an event that was being hosted by his wife. The students were allegedly taken by officers to the neighboring town of Cocula where they were said to have been turned over to members of the criminal gang Guerreros Unidos.
Earlier this week, some 500 teachers protested in the state capital, Chilpancingo, armed with pipes and sticks. They were said to have burst into the offices of the PRD, demanding Aguirre's resignation. Protests by demonstrators disillusioned with rule of law in Mexico have taken place in Iguala itself, in Mexico City, and as far afield as Buenos Aires and Berlin.
The 58-year-old was once a member of Mexican President Enrique Pena Nieto's Institutional Revolutionary Party (PRI). He had his first taste of power at state level while serving for the PRD as the Guerrero governor between 1996 and 1999. His predecessor resigned over a massacre of farmers by police.
rc/av (AFP, AP, Reuters)