People celebrate in favor of Peru's ex-president Alberto Fujimori in Lima on December 24. The president of Peru, Pedro Pablo Kuczynski, on Sunday granted a humanitarian pardon to Fujimori, who has been hospitalized since Saturday and is serving a 25-year sentence for crimes against humanity. Photo: AFP

Former Peruvian president Alberto Fujimori, who has been serving a prison term for crimes against humanity committed during his presidency, was hospitalized Sunday for the second time in a month, prison authorities announced in a statement.

The 83-year-old, who has served 15 years of a 25-year term, suffered a drop in blood pressure and an irregular heartbeat and was urgently transported to a hospital, where his condition was stabilized, the National Penitentiary Institute said on Twitter.

He was later transferred to a clinic for continued monitoring.

Fujimori, who suffers recurrent respiratory, neurological and hypertension problems - he had heart surgery in October - was hospitalized on March 3 after suffering a strong arrhythmia. 

After an 11-day stay, he was returned to the police base where he is the only prisoner.

His latest health crisis came a week after the Inter-American Court of Human Rights (IACHR) urged Peru to refrain from implementing a high-court ruling that would have freed Fujimori under a 2017 presidential pardon.

Lima has said it would abide by any IACHR decision.

Fujimori, who was president from 1990 to 2000, was subsequently jailed over massacres committed by army death squads in 1991 and 1992 in which 25 people were killed in supposed anti-terrorist operations.

AFP