U.S. Searches for Troops In NE Afghan Mountains

International aid organizations have pulled out of large swathes of the country, and in the capital, many foreign workers are largely confined to their compounds and offices. The chill deepened after Clementina Cantoni, 32, an Italian working for the United Nations, was kidnapped in the capital May 16 and held for three weeks before officials negotiated her release.

After successfully holding a presidential election last October, officials have begun preparing for a parliamentary vote in September, but the pre-election atmosphere this time is tense. Ethnic rivalries, the continuing power of regional militia bosses, and widespread corruption have marred election preparations.

Among all of the country's problems, the most serious appears to be the re-emergence of armed guerrillas. In the past three months, there have been dozens of attacks and clashes in several provinces. More than 400 suspected insurgents have been killed, along with several hundred Afghan civilians and soldiers. The U.S. military has suffered 45 deaths, including the 16 killed in the helicopter crash.

Until recently, the guerrillas have mainly clashed with troops in remote, rugged areas near the border with Pakistan, which, according to Afghan officials, they use as a haven. But the insurgents are increasingly targeting Afghan civilians.

On Thursday armed fighters kidnapped and killed a group of tribal elders in central Uruzgan province, then sent a boy to offer to exchange the bodies for those of dead militiamen who had been killed Wednesday while attacking a police station.

In other recent incidents, an Afghan election worker was shot in the face; six anti-drug workers were killed while driving the body of a slain colleague to Kabul; a prominent moderate Islamic cleric was assassinated; and, a suicide bomber killed 20 people at the cleric's funeral.

Staff writers Bradley Graham and Pamela Constable in Washington contributed to this report.