Iraqi President Jalal Talabani on Monday protested the arrest by U.S. forces of two Iranian envoys who were in Iraq at his invitation, a spokesman said.
Officials in Washington confirmed the detentions, first reported in the New York Times, saying the two officials were among an unspecified number of Iranians apprehended in raids last week aimed at groups suspected of plotting attacks against U.S. and Iraqi targets.
The incident underscored divergent approaches toward Iran's attempts to expand its role in Iraq and the containment of militant Shiite Muslim groups allegedly funded by Tehran.
President Bush has resisted pressure to open talks with Iran, which the United States accuses of arming and funding Shiite militiamen in Iraq. American officials have also accused Tehran of supplying technology used to make roadside bombs. Iran denies the U.S. charges, saying its ties to Iraq are political and religious.
"We suspect this event validates our claims about Iranian meddling, but we want to finish our investigation of the detained Iranians before characterizing their activities," White House spokesman Alex Conant said.
Iraqi officials have forged ahead with diplomatic contacts with Iran, and are distressed about a possible setback.
Last month, Talabani flew to Tehran to enlist the support of Iranian President Mahmoud Ahmadinejad in quelling the violence in Iraq and rebuilding its shattered economy. The two signed agreements aimed at boosting ties.
It was during the Tehran visit that Talabani extended the invitation to the two envoys who were detained last week, said Hiwa Osman, his spokesman. Talabani "is unhappy about the arrests" and has raised the issue with U.S. officials, Osman said.
He refused further comment. But a Kurdish political insider said the incident suggested a lack of communication between the United States and Iraq over security matters and relations with Iran.
"It seems that each side has their own plans and they are not coordinating with each other," said Mahmoud Othman, a lawmaker and Osman's father. "Of course it is of concern."
A U.S. military official said American troops were not targeting Iranians, and that they happened upon the two envoys during a routine counterinsurgency operation.
"We conducted a raid, we switched on the lights, and there they were," said the official, who spoke on condition of anonymity.
Conant said the two officials were handed over to the Iraqi government because they had diplomatic immunity, and that Iraqi officials had released them to Iranian authorities.
"We continue to work with the [Iraqi government] on the status of the remaining detainees," Conant said. "That investigation is going well."
Osman said he was not aware of any other arrests. None of the U.S. officials interviewed Monday would specify how many Iranians had been detained or provide details about the raids. Iraqi officials also refused to give details.
In Tehran, the Foreign Ministry called the arrest a "contravention of the code of conduct with diplomats," the official Iranian news agency reported. It quoted a ministry official as saying the arrests could have "unpleasant consequences."
Washington and Tehran broke formal diplomatic ties after Iranian radicals stormed the U.S. Embassy in Tehran in the 1979 Islamic Revolution, which brought to power the world's first Shiite Muslim theocracy.
The New York Times reported Sunday that the U.S. military was holding at least four Iranians, including senior military officials detained in two raids. It said the diplomats were apprehended Thursday while traveling in an Iranian Embassy vehicle. Embassy officials refused to comment Monday.
Hadi Amiri, a leading figure in the political party of Shiite power broker Abdelaziz Hakim, denied the newspaper's report that some of the arrests were made at his home.
Iran has forged close ties to senior members of the Shiite political alliance that leads Iraq's government, including Hakim, who spent years in exile in Iran during the rule of former Iraqi leader Saddam Hussein.
Zavis reported from Baghdad and Spiegel from Washington. Times staff writers Raheem Salman and Molly Hennessy-
Fiske contributed to this report from Baghdad.