Iran's Islamic Revolutionary Guard Corps (IRGC) on Sunday (September 9th) confirmed it had launched deadly missile strikes against a Kurdish opposition group in northern Iraq, AFP reported.

In a statement carried by its Sepah News website, the IRGC said seven surface-to-surface rockets fired Saturday by the missile department of the IRGC’s aerospace force had hit the headquarters of the Kurdistan Democratic Party of Iran (KDPI) in Koysinjaq, east of Erbil.

The IRGC’s drone division also was involved, the statement said.

Fifteen people were killed in the rare cross-border attack on the KDPI, which is blacklisted as a "terrorist" group by Tehran, KDPI spokesman Soran Louri told AFP on Sunday.

Around 30 others were injured, according to local medical sources.

The KDPI had recently clashed with IRGC forces in the towns of Marivan and Kamyaran in Iran's own Kurdistan region, the statement said.

The Kurdish group was holding a meeting at the time of the strikes, and the party's secretary general and his predecessor were injured, an official said.

Iraq's foreign ministry denounced the Iranian missile strike.

"Iraq protects the security of its neighbours and does not allow its territory to be used to threaten these countries," spokesman Ahmed Mahjoub said in a statement. "But it categorically rejects the violation of its territorial sovereignty by strikes against certain targets on its territory with previous co-ordination."

The KDPI is Iran's oldest Kurdish movement and has seen several of its leaders assassinated by Tehran in the past.