ARBIL, Iraq - US forces stormed an Iranian consular office in the northern Iraqi Kurdish city of Arbil early on Thursday and arrested five people, including diplomats and staff, Iranian officials said.

US soldiers patrol a road in Baghdad in this October 27, 2006 file photo. US forces raided the Iranian consulate office in the northern Iraqi city of Arbil on Thursday and arrested five employees, the official Iranian news agency IRNA said. [Reuters]

The US military made no direct mention of Iranians but in answer to a query issued a statement saying six "individuals" were arrested during "routine" operations in the area.

As the overnight raid was in progress, President George W. Bush was vowing in a keynote address on American television to disrupt what he called the "flow of support" from Iran and Syria for insurgent attacks on US forces in Iraq.

Iranian Foreign Ministry spokesman Mohammad Ali Hosseini condemned the raid -- the second such operation in the past month as tensions between Washington and Tehran have mounted -- and said it was a violation of international law.

"The activity of all those people at our office in Arbil was legal and was in cooperation with and had the approval of the Iraqi side," Hosseini told Iran's state-owned Arabic language satellite channel Al-Alam.

"There is no justification for this behavior of the Americans, particularly because Iraqi officials were not informed about this move."

In a statement, the US military said it had detained six people around Arbil on suspicion of being "closely tied to activities targeting Iraqi and coalition forces."

"This operation was part of an ongoing effort by coalition forces targeting individuals involved in activities aimed at the killing of Iraqi citizens and Coalition forces," it said, adding the suspects surrendered without incident.

US Secretary of State Condoleezza Rice, while not commenting on the operation in Arbil, told Fox News:

"The president made very clear last night that we know that Iran is engaged in activities that are endangering our troops, activities that are destabilizing the young Iraqi government and that we're going to pursue those who may be involved in those activities."

TEHRAN DENIES MEDDLING

Witnesses in Arbil, the capital of the autonomous northern region of Kurdistan bordering Iran, said Kurdish security forces sealed off the area after the Americans left. The Kurdish regional government made no immediate comment.

The official Iranian IRNA news agency said documents and computers were seized after the 5 a.m. (0200 GMT) raid and Iranian state television said the arrested included "diplomats and staff."

US officials have repeatedly accused non-Arab, Shi'ite Iran of interfering in Iraq, where the long-oppressed Shi'ite majority is now in power. Tehran denies US charges of supplying Shi'ite militias with weapons.

In December, US forces in Baghdad arrested a number of Iranians they said were suspected of planning attacks on Iraqi security forces, including diplomats who were later turned over to Iraqi authorities.

A British official told the BBC this month that the Iranians arrested in Baghdad were senior intelligence officers on a covert mission to influence the Iraqi government.

Iraqi government spokesman Ali al-Dabbagh, whose boss Prime Minister Nuri al-Maliki traveled last year to Tehran as part of a series of high-level contacts that have sealed a warming of relations between former enemies Iraq and Iran, said Baghdad had demanded an explanation from Iran and Washington on the matter.