BAGHDAD, Iraq -- U.S.-led forces detained five Iranians Thursday after a raid on a government office flying an Iranian flag, Iraqi officials and witnesses said, as President Bush vowed to isolate Iran and Syria as part of a new strategy to quell violence in Iraq. The multinational forces entered the building overnight, detained the Iranians and confiscated computers and documents, two senior local Kurdish officials said, speaking on condition of anonymity because of the sensitivity of the information. Six people suspected of being involved in attacks against Iraqi civilians and military forces were initially detained, the U.S. military said in a statement. One was later released.
The statement did not identify the nationalities of the suspects.
ABC News, quoting Iraq's Foreign Minister Hoshyar Zebari, reported that U.S. forces tried and failed later Thursday to seize more people at Irbil's airport. That raid resulted in a tense, armed standoff with Kurdish peshmerga militia forces, the television news organization said.
"There weren't any casualties, but it was a split second really for a disaster to happen," Zebari told ABC News.
The arrests in Irbil drew condemnation from the regional Kurdish government and concern from Iraqi officials in Baghdad, who are trying to maintain close ties with both Iran and the U.S. despite the hostility between the two. It was the second effort by the U.S. to target Iranians in less than a month.
The raids also came as U.S. officials repeated long-standing accusations that Iran is encouraging the violence in Iraq by supplying money and weapons.
"I think it's instructive that in the last couple of weeks two of those raids that we conducted to go after these folks that are providing these kinds of weapons -- two of those raids had policed up Iranians," Gen. Peter Pace, chairman of the Joint Chiefs of Staff, said in Washington. "So it is clear that the Iranians are complicit in providing weapons."
In Tehran, Iran's Foreign Ministry said it summoned the Iraqi and Swiss ambassadors and "demanded an explanation" about the Irbil incident. Switzerland represents American interests in Iran.
A resident near the Iranian office in Irbil said foreign forces used percussion grenades and brought down an Iranian flag from the roof of the yellow, two-story building. As the operation continued, two helicopters flew overhead, the resident said, speaking on condition that his name not be used because he feared retribution.
In the afternoon, Kurdish militiamen surrounded the building, preventing people from approaching. They did not allow cameramen and photographers to take pictures.
Irbil is in the Kurdish-controlled north, a relatively peaceful part of the country 220 miles from Baghdad.
Zebari told ABC News that the U.S. forces at the airport refused to identify themselves. "They were unwilling to reveal their identity and entered the airport, which is a very sensitive area, and there was a response by the local forces," he was quoted as saying.
U.S. Ambassador Zalmay Khalilzad said the detained Iranians were being questioned.
Tensions are high between Iran and the United States. The Bush administration, which sent troops to Iraq in 2003 to oust Saddam Hussein, has accused Tehran of seeking to develop nuclear weapons and of helping fuel violence in Iraq. Iranian President Mahmoud Ahmadinejad, meanwhile, is trying to expand Tehran's role in Iraq to counter U.S. influence in the region.
Iraqi government spokesman Ali al-Dabbagh said the government was seeking clarification from the Americans and the Iranians about the detainees. He chided both sides, along with Syria, for using Iraq to fight their political battles.
"Sometimes we pay the price for the tension in relations between Iran and the United States and Syria, therefore it is in our interest ... that these relations improve, but not at the expense of Iraq," he said.
A bipartisan U.S. panel, the Iraq Study Group, in December called for a new diplomatic drive to enlist Syria and Iran in peace efforts. Instead, Bush accused both countries of aiding terrorists and insurgents in Iraq in his speech Wednesday outlining his new war strategy.
"We will disrupt the attacks on our forces," Bush said. "We will interrupt the flow of support from Iran and Syria."
Iraqis expressed skepticism that Bush's plan to send in 21,500 more troops will quell the violence in their country.
On Thursday, police reported at least 45 people were killed or found dead from bombings and shootings, including a 10-year-old struck in a mortar attack in the northern city of Mosul and 37 tortured bodies found in Baghdad.
Gunmen ambushed a minivan carrying Oil Ministry employees in a predominantly Shiite area of Baghdad, kidnapping six of the passengers and the driver after separating people according to their IDs, police said.
Prime Minister Nouri al-Maliki announced Saturday that his government would implement a new security plan for Baghdad, including neighborhood-by-neighborhood sweeps by Iraqi forces backed by U.S. troops. Similar efforts have failed in the past. The Bush proposal calls for up to 12,000 additional Iraqi troops to secure Baghdad.
Foreign Minister Hoshyar Zebari welcomed both plans and promised the "strategy will be followed in order to bring increase security and stability in the capital, Baghdad, and the other provinces."
"This plan did not come by itself but the Iraqi government contributed to it and it came after close consultations between the Iraqi government and the American administration," he added.
But Sunni lawmaker Hussein al-Falluji opposed the deployment of more U.S. troops in Iraq and called instead for a timetable for U.S. withdrawal. And Adnan al-Dulaimi, leader of parliament's largest Sunni Arab bloc, urged the Americans and the Iraqi government to disband Shiite militias.
Some Iraqis wearily welcomed any effort to stop the carnage.
"The security situation in Iraq is very bad, we are facing death at any moment daily," said 35-year-old Awad Mukhtar. "I see the new Bush strategy as the last chance for Iraqis to save their lives ... we have no other choice, only to wait and see the results."
Iraqi and Iranian officials initially said the Iranian office raided in Irbil was a diplomatic mission. But Mohammad Ali Hosseini, Iran's Foreign Ministry spokesman, later changed the description to an "office of relations."
"The office was waiting for permission from the Iraqi authorities to operate as a consulate," Hosseini said, according to Iranian state television.
He did not describe the Iranians who worked there as diplomats. "The office was established in coordination with, and with the agreement of, the Iraqi authorities," Hosseini said. "It was performing some consular affairs."
At the Pentagon, a senior U.S. military official said the building was not a consulate and did not have diplomatic status. The six Iranians were taken in a "cordon-and-knock" operation, said the official who spoke on condition of anonymity because he was not authorized to release the information.
The regional Kurdish government condemned the arrest of the Iranians and called for their release. Many Kurds, including President Jalal Talabani, have close ties to Iran.
Last month, U.S. troops detained at least two Iranians and released two others who had diplomatic immunity. Two of those detained were visiting as guests of Talabani, his spokesman said.
Associated Press writers Bassem Mroue and Qassim Abdul-Zahra in Baghdad; Nasser Karimi in Tehran; and Pauline Jelinek in Washington contributed to this report.