By LARRY ROHTER
 
BUENOS AIRES, Nov. 15 — When President Néstor Kirchner moved to purge the armed forces and Supreme Court immediately after taking office in May, both institutions rapidly bowed to his will. But now that he is taking on a corrupt police force he says is responsible for a recent epidemic of kidnappings, he seems to be meeting stiff resistance.

On a recent trip to his home province in Patagonia, Mr. Kirchner received death threats on a cellphone, aides said. The warnings, which included information describing the daily movements of his children, came the day after Mr. Kirchner ordered "a complete cleansing" of the 47,000-member Buenos Aires provincial police as part of a broader "No Impunity Plan" for combating entrenched police corruption.

Since January, nearly 200 kidnappings have occurred in and around Buenos Aires, where about half of Argentina's 37 million people live. The most widely publicized cases involved members of prominent business families and relatives of soccer stars, but dozens of less-affluent people have also been abducted and held for smaller ransoms.

Mr. Kirchner said this month that members of the police, many from the Buenos Aires provincial force, were suspected of involvement in most of these cases. "Anywhere you touch, pus oozes from" law enforcement units, he added, vowing to comply with what he said was "the political and moral obligation to purify all of the country's police forces."

Crime has increased in Argentina after an economic collapse in December 2001 forced more than half the population below the poverty line and pushed unemployment to more than 20 percent. But the anxiety level has recently grown because of a case in which the finger of a kidnapped college student was amputated by his captors, who sent it and a video of the amputation to his family to persuade them to pay a $150,000 ransom.

As a result, public security has vaulted to the top of concerns among the populace. The government campaign was announced soon after pot-banging demonstrators took to the streets two weekends ago to protest the crime wave, using the same tactics that toppled President Fernando de la Rúa two years ago.

Responding to Mr. Kirchner's call to "exercise authority with force," the provincial governor of Buenos Aires, Felipe Solá, has ordered 5,000 more officers into the streets. But some critics have said they fear that will only compound the problem, given evidence of the provincial force's involvement in gambling, prostitution, drug trafficking, car theft and truck hijackings.

This week, the director of the provincial antikidnapping unit, who earns less than $1,000 a month, was fired after it was discovered he had a yacht and a mansion he used as a weekend getaway. Other local police chiefs were also replaced this month after being accused of taking bribes.

But there is a more directly political subtext to the campaign. Mr. Kirchner is eager to establish his independence from his predecessor, Eduardo Duhalde, a fellow Peronist who was governor of Buenos Aires during most of the 1990's and even called the provincial police "the best in the world."

Mr. Duhalde remains at the head of the Peronist political machine in the province, which provided Mr. Kirchner with his margin of victory in the April election. Books and press reports here say at least part of the money collected by the police from their illegal activities sustains the Peronist apparatus, so by striking at police corruption, Mr. Kirchner is in theory also weakening his rivals within the party.

"There are politicians who are thieves and finance their campaigns with money from police corruption," Justice Minister Gustavo Beliz, said last week. "The problem is that the police forces have been corrupted because there have been criminal politicians who have made deals with them, and so they have not been capable of a thorough overhaul."