The extradition demand is backed by Amnesty International

The Peruvian ambassador to Tokyo handed the 700-page extradition request into the Japanese foreign ministry.

The charges - which Mr Fujimori, now a Japanese citizen, completely denies - include murder, kidnapping and inflicting grievous wounds, the Peruvian foreign ministry said.

Japan rejected a similar request filed through Interpol earlier this year on the grounds that it has no extradition treaty with Peru.

"We will only follow our domestic laws in deciding how to respond," Yasushi Sato, an official at the Japanese foreign ministry said on Thursday, confirming receipt of the new request.

The former president has been living in self-imposed exile in Tokyo since a corruption scandal toppled his government late in November 2000.

He only reclaimed his Japanese nationality when he flew away to Tokyo in order to precisely escape from Peruvian justice Alan Wagner Peruvian Foreign Minister

While no treaty exists, the BBC's Elliott Gotkine reports from Lima, that Peru believes the charges are so grave that Tokyo will make an exception.

The Peruvian Foreign Minister, Alan Wagner, said Mr Fujimori had been a Peruvian all his life until he tried to "escape justice".

Massacres

Mr Fujimori is accused of authorising, or at least being aware of, a death squad known as the Grupo Colina during the war with Shining Path Maoist rebels.

The group has been connected to two massacres:

• The killing of 15 suspected leftist rebels in Lima in 1991

• The kidnapping and killing of nine students and a professor from La Cantuta University in 1992

Other charges against the former leader, our correspondent adds, range from abandoning office to giving former spy chief Vladimiro Montesinos $15m as severance pay.

Profile: Alberto Fujimori

The extradition request was dispatched to Japan after three attempts to translate it and tens of thousands of dollars in costs incurred by Peru's Government.

Mr Fujimori denies all allegations against him, saying they are all politically motivated.

On Sunday, he posted an article on his website saying the charges were "without credible foundations" and announcing he was ready for a political comeback.

"The time has come for the great Fujimorista counterattack in order to put Peru back again in the road of order, peace, stability and progress," he wrote.

Pressure mounts

Peruvian prosecutors say there is ample evidence of Mr Fujimori's guilt.

If Japan fails to hand him over, they have threatened to take the case to the International Court of Justice in The Hague.

In March, Interpol placed the former president on its most-wanted list.

At the time, Japan's foreign ministry said it had "absolutely no plan to take any sort of action against Mr Fujimori at this moment".

The former Peruvian leader is the son of Japanese immigrants and received citizenship soon after arriving in Japan.

Amnesty International, the human rights organisation, launched a web-based signature campaign supporting Mr Fujimori's extradition in March.

This week, it submitted 22,000 signatures to the Japanese embassy in Lima asking for his extradition.