Updated

Former Peruvian President Alberto Fujimori's chief doctor says he has been hospitalized for surgery to correct lesions on his tongue.

Dr. Alejandro Aguinaga tells The Associated Press that Fujimori entered a hospital Sunday. It will be the fourth time since 1997 that he has undergone such an operation.

Aguinaga says the procedure is scheduled for Monday morning.

The 71-year-old former leader is serving a 25-year jail sentence for killings and kidnappings by security forces during his presidency.

Fujimori ruled Peru with an increasingly iron fist from 1990 until 2000, when his government collapsed amid a bribery scandal.

In 2005 he left exile in Japan and traveled to Chile, where he was arrested and extradited to Peru.