By TYLER BRIDGES

LIMA - Former Peruvian President Alberto Fujimori was arrested in Chile early Monday, a dozen hours after defying an international arrest order by arriving unannounced in Chile from Japan as part of a high-stakes bid to return to Peru to run for president.

The unusual late-hour arrest came at the request of authorities in Peru, where Fujimori, who served as president from 1990 to 2000 and then fled to Japan, is wanted on 21 corruption and human rights charges.

Initially, it had appeared that Fujimori would remain free in Chile as he passed through immigration with four others and went straight to the Marriott Hotel in Santiago. Chilean officials had declined to detain him, saying that there was no arrest order for him in the country.

But after Judge Orlando Alvarez issued an arrest order, police took Fujimori from the Marriott early Monday to a police academy.

Peruvian officials will be filing a request to extradite Fujimori to Peru as soon as possible. Under Chilean law, the extradition request cannot be heard for at least 15 days after it has been filed.

Monday's arrest capped a flurry of legal and political activity in Peru and Chile that was set off by Fujimori's unexpected arrival Sunday afternoon to Santiago.

Peru's El Comercio newspaper reported in its edition Monday that Fujimori initially flew from Tokyo to Atlanta on Delta Airlines and then took a private plane to Santiago, with a stop in Tijuana.

An official from Interpol in Santiago told reporters Sunday afternoon that the ex-president wasn't detained because there is no Chilean judicial arrest order for him.

Fujimori flew to Chile as part of a strategy to win back the presidency.

''It is my purpose to remain temporarily in Chile, as part of the process for my return to Peru,'' Fujimori said in a statement issued by his office in Lima Sunday afternoon. Fujimori wants to ``fulfill my pledge to an important sector of the Peruvian people that has called on me to participate as candidate to the presidency of the Republic in the coming election in 2006.''

Exactly how Fujimori, 67, could return to Peru to run for president remains uncertain since Peruvian authorities have said they plan to put him behind bars and on trial. They have been trying to extradite him from Japan without success.

Fujimori has been saying for months that he would return to Peru to run for president once again in the upcoming elections. He has been running a virtual campaign from the Tokyo hotel that doubled as his home, e-mailing supporters, updating his web page and recording weekly radio pronouncements broadcast in Peru.

Fujimori retains fervent support from many low-income Peruvians who affectionately call him ''El Chino,'' or ''the chinaman,'' a common nickname in Peru for anyone with Asian features.

Rising crime has many Peruvians yearning for Fujimori's strong hand, while others disgusted with the political problems of Toledo -- who has an abysmal approval rating of 15 percent -- say Fujimori would straighten out the country.

''We're thrilled to have him nearby,'' Martha Moyano, one of only two members of Congress who support Fujimori, said Sunday. ``We are out in the streets celebrating, as are people throughout Peru.''

But many Peruvians, including President Toledo and nearly all media outlets, regard him as nothing more than a fugitive from justice. They say that Fujimori's departure restored democracy to Peru.

''We who fought against the dictator hope that the Chilean government will do what it should do: arrest him,'' Baruch Ivcher, owner of one of Peru's national television networks, said Sunday night. Ivcher fled Peru to avoid arrest by the government after his station exposed dirty dealings by the Fujimori government in 1997. He returned only after Fujimori left office.

Many analysts had expected Fujimori to remain in Japan. He is wanted on charges in Peru ranging from misuse of public money to abuse of power to sanctioning paramilitary squads that killed government opponents. Peru's Congress has also prohibited him from holding office until 2011.

As president, Fujimori won enemies by governing with a heavy hand -- he simply shut the Congress in 1992, overriding objections that he had no right to do so -- but he won widespread support from ordinary Peruvians for vanquishing the Shining Path guerrillas, extinguishing hyperinflation and overseeing the country's rebound in the 1990s.

Recent polls show him with 20 to 25 percent in the wide-open presidential race, or about as much as any of the other candidates. The primary is in April; the top two finishers face-off in June.

But polls also show that 60 percent of Peruvians detest Fujimori, indicating that even if he makes the second round, he would have little chance of winning the presidency again.

Fujimori resigned unexpectedly in November 2000, six months after winning office a third time amidst a widening corruption scandal. He resigned by fax while visiting his parents' native Japan.

Fujimori was a political unknown -- he had been the chancellor of the national agrarian university -- when he was elected president in 1990, at a time when the country seemed ungovernable. He won re-election twice more, in 1995 and 2000, with the latter victory marred by charges of vote-buying and bribing political opponents.

In all, 42 people have been convicted of crimes involving the Fujimori government, special anti-corruption prosecutor Antonio Maldonado said two months ago. He added that the Toledo government has collected $162 million illegally stashed abroad by Fujimori's cronies.

Fujimori's arrival in Chile comes at a difficult time for relations between Peru and Chile. Peru's Congress last week unanimously approved a resolution claiming rights to an area of the ocean off the coast of both countries that Chile has long claimed as its own.

Special correspondent Alejandra Matus in Santiago contributed to this report.