BAGHDAD, Iraq - The Iraqi foreign minister said Friday that the five Iranians detained by U.S.-led forces in Kurdish-controlled northern Iraq were working in a liaison office that had government approval and was in the process of being approved as a consulate.

Foreign Minister Hoshyar Zebari, a Kurd, also said U.S. forces tried to seize more people at the airport in Irbil, 220 miles north of Baghdad, prompting a confrontation with Kurdish troops guarding the facility that was resolved without casualties. The U.S. military did not immediately comment on that incident.

The arrests drew condemnation from local Kurdish authorities, who protested that they were not informed in advance, and have raised fears that tensions between Iran and the United States were hurting Iraq's interests.

"We don't want Iraq to be a battleground for settling scores with other countries," Zebari told CNN later in an interview.

Radical Shiite cleric Muqtada al-Sadr's office, meanwhile, rejected President Bush's plans to send 21,500 more American troops to Iraq as part of a wide-ranging new effort to curb rampant sectarian attacks.

"We reject Bush's new strategy and we think it will fail," said Abdul-Razzaq al-Nidawi, a senior official in al-Sadr's office in the Shiite holy city of Najaf.

He said Iraq's problems were due to the presence of U.S. troops and called for their withdrawals.

"We call upon the American people to oppose sending more of their sons to Iraq so that they will not be flown back in coffins," he said.

The Iranians were detained Thursday as multinational forces entered the building overnight 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.

Iraqi and Iranian officials initially said the Iranian office raided in Irbil was a diplomatic mission, which raised questions about whether those detained had diplomatic immunity. But Zebari told The Associated Press that the Iranians worked at a "liaison office" that was in the process of becoming a consulate.

"This office is not new and has been there for more than 10 years," he said. "We are now in the process of changing these offices to consulates and ... we will open consulates in Iran."

Mohammad Ali Hosseini, Iran's Foreign Ministry spokesman who initially said it was a diplomatic mission, later changed the description to an "office of relations" and said it was waiting for permission to operate as a consulate.

The U.S. Embassy also said it was assured the building was not a consulate.

"The government of Iraq has indicated through formal diplomatic channels that the Irbil office was not accredited as a consulate and it has not asserted that the detained individuals have diplomatic privileges and immunities," embassy spokesman Lou Fintor said.

The regional Kurdish government condemned the arrest of the Iranians and called for their release. Many Kurds, including Iraqi 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.

Zebari also said American forces went to the Irbil airport on Thursday but didn't identify themselves or give advance notice to local authorities.

"No party had knowledge of this matter and that is why the force protecting the airport tried to interfere and find out who they were and what they were doing," he said. "Later it became clear that they are American special forces looking for people that did not exist."

The concerns expressed by Kurdish authorities, who have been among the staunchest supporters of U.S. efforts in Iraq, reflected the difficulties they face in trying to maintain close ties with both Iran and the U.S. despite the hostility between the two.

The raids came as U.S. officials repeated long-standing accusations that Iran is encouraging the violence in Iraq by supplying money and weapons. Bush vowed to isolate Iran and Syria as part of his new war strategy.

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.

U.S. Ambassador Zalmay Khalilzad said Thursday that the detained Iranians were being questioned. But the U.S. Embassy declined to give an update on their status on Friday.