The former Peruvian president Alberto Fujimori was today convicted of kidnapping and murder and sentenced to 25 years in what was described as a landmark ruling for human rights cases in Latin America.

A three-judge panel found the 70-year-old guilty of authorising a military death squad during the state's "dirty war" against Maoist rebels in the 1990s.

The 15-month trial, held at a special forces police base just outside the capital, Lima, was the first time a democratically elected Latin American leader had been tried on home soil for human rights abuses.

"This court declares that the four charges against him have been proven beyond all reasonable doubt," Judge Cesar San Martin told the courtroom.

Observers said the marathon case – involving 80 witnesses, 160 sessions and a 711-page ruling – continued a trend towards bringing rogue former heads of state to book.

"After years of evading justice, Fujimori is finally being held to account for some of his crimes," Maria McFarland, a Human Rights Watch researcher who attended, said.

"With this ruling, and its exemplary performance during the trial, the Peruvian court has shown the world that even former heads of state cannot expect to get away with serious crimes."

Outside the tribunal, violent clashes flared between rival groups of supporters and opponents of the accused, underlining Peru's split over whether he was a hero or villain.

A university chancellor and political outsider who unexpectedly won power in 1990, Fujimori crushed a terrorist insurgency and tamed rampant inflation, paving the way for stability.

But corruption and murderous excesses marred his autocratic rule until his fall in 2000 when he fled to Japan, his parents' homeland, and faxed his resignation.

Fujimori attempted a political comeback in 2005 when he flew to Chile in the run-up to Peru's presidential election, only to be arrested and extradited in 2007.

Fujimori protested his innocence and said he deserved credit for saving Peru from anarchy.

"I governed from hell, not the palace," he told the court. He blamed his former spy chief, Vladimiro Montesinos, for any counter-insurgency excesses.

An estimated 70,000 people died during the leftist Tupac Amaru and Maoist Shining Path insurgencies.

Around 37% were killed by the military, according to Peru's Truth and Reconciliation commission.

The court convicted Fujimori of the deaths of 25 people in two massacres and the kidnapping of a businessman and a journalist.

The massacres were carried out by the Colina unit, consisting of specially trained military intelligence officers.

In the first, the unit used silencer-fitted guns to shoot 15 people at a chicken barbecue in Lima in 1991, mistaking them for guerrilla sympathisers.

The following year, it abducted and "disappeared" nine university students and a professor.today.