BAGHDAD, Iraq -- Five Iranians seized by U.S.-led forces were working in a longtime government liaison office that was being upgraded to a consulate, the Iraqi foreign minister said Friday.

Tehran condemned the U.S. raid in the Kurdish-controlled northern city of Irbil and urged Iraq to push for the Iranians' release.

Iraqi Foreign Minister Hoshyar Zebari said the building where the Iranians were detained Thursday had operated with Iraqi government approval for 10 years.

"We are now in the process of changing these offices to consulates," he said. "It is not a new office. This liaison office has been there for a long time."

He also echoed concerns the U.S. and Iran were dragging Iraq into their fight. "We don't want Iraq to be a battleground for settling scores with other countries," Zebari, an Iraqi Kurd, told CNN.

In Washington, Deputy U.S. State Department spokesman Tom Casey said that the U.S. forces entered the building in Irbil because information linked it to Iranian elements engaging in violent activities in Iraq.

The diplomatic tussle came at an unwelcome time for the United States as President Bush faces criticism over his new strategy for ending the violence in Iraq. Bush also vowed to isolate Iran and Syria, which the U.S. has accused of fueling attacks in Iraq.

Iraqi President Jalal Talabani plans a trip to Syria on Sunday, the highest-level Iraqi visit to the country in more than 24 years.

Zebari's Iranian counterpart, Manouchehr Mottaki, called on the Iraqi government to secure the release of the five Iranians, Iranian state television reported.

Mottaki condemned the raid, saying it contravened the Vienna Convention.

Russian Foreign Ministry spokesman Mikhail Kamynin also harshly criticized the detentions, calling them a "flagrant violation" of international conventions.

"It's absolutely unacceptable when the military storms a foreign consular office on the territory of another state," Kamynin said. "The unlawful actions by the U.S. servicemen mark an open abuse of a mandate issued to the multinational forces in Iraq."

Zebari 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.

A Pentagon official in Washington said that after troops detained the Iranians, they learned another person might have escaped and fled to the airport. An American team went to the airport, where they "surprised" Kurdish forces, who apparently had not been informed they were coming, the Defense Department official said.

Meanwhile, sectarian violence persisted. At least 19 people were reported killed or dead nationwide.