Police in Chile have arrested fugitive Peruvian ex-President Alberto Fujimori just hours after he began a surprise visit to the country.
Fujimori had said he hoped to return to Peruvian politics
He is wanted in his home country on corruption and human abuse charges.
Although Peruvian warrants for his detention were thought invalid in Chile, a judge ordered his arrest after Peru lodged an extradition request.
Mr Fujimori, who denies any wrongdoing, said he was visiting Chile as part of a bid to return to Peru and stand for president in 2006.
He was picked up at a Santiago hotel at 0430 GMT and surrendered without resistance, according to authorities.
The Peruvian government is sending a delegation to Chile led by Interior Minister Romulo Pizarro in a bid to speed up Mr Fujimori's extradition.
Correspondents say that the former president's arrival in South America was a surprise for both the Chilean and Peruvian governments.
Mr Fujimori had so far preferred to conduct his unofficial electoral campaign from Japan, where he has been living in self-imposed exile.
He received Japanese citizenship after fleeing Peru in 2000. Tokyo has repeatedly turned down repeated requests from Lima for his extradition.
Even though Chile and Peru have had an extradition treaty for more than 70 years, it is not clear if arrest warrants issued by Interpol are legally binding on Chile.
Chilean Judge Orlando Alvarez, entrusted with considering Peru's extradition request, ordered Mr Fujimori's arrest and he will be held while the matter is being decided.
The head of Interpol in Chile, Maria Elena Gomez, said earlier the authorities were aware of Mr Fujimori's presence.
"There are several international arrest warrants against Alberto Fujimori, which are not legally valid in Chile," Ms Gomez added.
She said that he was free to leave the country when he wanted.
Mr Fujimori, 67, had said he planned "a temporary stay in Chile as part of a return to Peru to keep a promise with a large part of the people of Peru" to stand again for president next April.
He is banned from holding public office there until 2010.
The BBC's James Painter says that another complicating factor is that Mr Fujimori's arrest comes at a time of worsening relations between Chile and Peru in a dispute over their sea border.
The Chilean government may be reluctant to do Peru any favours, he adds.
Last week, Mr Fujimori announced in Tokyo the formation of an alliance to strengthen his electoral chances.
On Sunday, several hundred of his supporters, who remember his success in beating hyperinflation and for crushing the Shining Path rebels, staged a demonstration in the Peruvian capital.
Fujimori supporters rallied in Peru at news of the Chile visit
Recent opinion polls suggest he is trailing way behind other candidates.
Correspondents say he may be calculating that a period of detention either in Chile or Peru may remind Peruvians of his presence and allow him to pick up some sympathy by portraying himself as a martyr.
Mr Fujimori - whose parents were originally from Japan - was Peru's president from 1990 to 2000.
The former president has been accused of involvement in the killing of 25 suspected members of the Shining Path guerrilla group by death squads, and also faces corruption charges.
Mr Fujimori denies any wrongdoing and believes he can win the vote. He was recently given a new Peruvian passport.