LIMA, Peru - Waving his arms in outrage and shouting that he is innocent, Alberto Fujimori went on trial yesterday on charges of using a death squad to kill leftist guerrillas and collaborators.

It is the first time in Peru's history that a former president faces a trial for crimes committed during his administration - and one of the few cases of a Latin American leader being tried after leaving office. The case is stirring mixed emotions in a country where many still admire Fujimori for defeating a bloody insurgency.

He led Peru from 1990 to 2000.

Fujimori faces charges he authorized the 1992 death-squad slayings of nine students and a professor at La Cantuta University, and the 1991 killings of 15 people in a Lima tenement. If convicted, he could be sentenced to as many as 30 years in prison.

As the morning session drew to a close, Fujimori, 69, who had shown no emotion until that point, asked permission to speak. Standing and waving his arms in outrage, he said he had inherited a nation on the edge of anarchy when he took office.

"I received a country . . . almost in collapse, exhausted by hyperinflation, international financial isolation and widespread terrorism," he said, his voice cracking. "My government rescued the human rights of 25 million Peruvians with no exceptions. If any detestable acts were committed, I condemn them, but they were not done on my orders. I reject the charges totally. I am innocent and do not accept the prosecutor's accusation."

Defense attorney Cesar Nakazaki said he would call witnesses from the armed forces and antiterrorism police to rebut the prosecution's assertion that Fujimori authorized a clandestine dirty war against the Maoist Shining Path guerrillas.

Prosecutor Jose Pelaez argued that Fujimori had put his closest adviser, intelligence chief Vladimiro Montesinos, in charge of the armed forces and was told of their actions.