TEHRAN

An Iranian Foreign Ministry spokesman on Monday said the practice of raising the Kurdish regional flag over public institutions in Iraq’s northern city of Kirkuk was a violation of Iraq’s national charter.

"Raising the [Kurdish regional] flag beside the Iraqi national flag [in Kirkuk] is contrary to Iraq's constitution," ministry spokesman Behram Kasimi said in a Monday statement.

He went on to describe the practice as "illegal” and one that threatened to “raise tension” in the region.

During the U.S.-led invasion of Iraq in 2003, Kurdish Peshmerga forces seized Kirkuk, prompting an influx of Kurds into the ethnically diverse city.

While Baghdad says Kirkuk is administratively dependent on Iraq’s central government, the Patriotic Union of Kurdistan -- an influential political party in the region -- wants to see the city incorporated into northern Iraq’s semi-autonomous Kurdish region.

Kirkuk’s population is composed mainly of Arab, Turkmen and Kurdish inhabitants.

*Reporting by Mustafa Melih Ahiskali; Writing by Emin Avundukluoglu