The announcement comes at a time of heightened tension in Iraq's autonomous Kurdistan region, where the Turkish army is conducting operations against the Kurdistan Workers' Party (PKK), which is listed as a "terrorist" group by Ankara and several Western allies.

The region is also scheduled to hold much-delayed elections in October.

The fires in 2023 and 2024 struck markets and shopping centres in the cities of Kirkuk, Arbil and Dohuk, Iraqi interior ministry spokesman Moqdad Miri said during a press conference, adding that the suspects made "confessions".

One suspect was arrested at the end of May and "chemical products" used to start fires were found in his vehicle, Miri said.

"The entity responsible for execution... is the PKK organisation, a banned organisation," he added.

The objective was to "harm the commercial interests of a country with which they are in direct opposition," as well as "to impact the security and economic situation" of the autonomous Kurdistan region, he added.

In a statement, the PKK's political bureau "rejected" what it said were "baseless allegations".

It called on "the Iraqi state and the ministry of the interior to act responsibly in the face of directives coming from Turkish intelligence" and to "identify the real perpetrators" of the fires.

- Strained ties -

The PKK, which has fought a decades-long insurgency against the Turkish state, has a presence in northern Iraq, as does Turkey, which has operated from several dozen military bases there against the Kurdish group.

Turkey's military operations, which sometimes take place deep inside Iraqi territory, have frequently strained bilateral ties.

During the joint conference, a senior official from Kurdistan's interior ministry, Hemin Mirany, revealed the identity of two of the suspects, saying that one belonged to the local Peshmerga armed forces.

The other suspect was an "officer in the anti-terrorist services of Sulaimaniyah", Kurdistan's second city, Mirany said.

The Kurdish official said the two men were "recruited" by the PKK and were "trained by fighters coming from Turkey and Syria in particular".

The three suspects were presented at the conference wearing yellow prison outfits, kneeling, blindfolded and handcuffed with their hands behind their backs.

Officials in both Turkey and Arbil, the capital of the Kurdistan region, have accused the PKK of benefitting from support within the Patriotic Union of Kurdistan (PUK), a major political party which controls the security services in Sulaimaniyah.

Responding to a request for comment, a PUK spokesman, Saadi Ahmed Pire, told AFP the anti-terrorism officer arrested had been "immediately removed" eight months ago when federal authorities first warned them that the individual had been accused.

In March, following a visit by senior Turkish officials to Iraq, Baghdad quietly listed the PKK as a "banned organisation" -- though Ankara demands that the Iraqi government do more in the fight against the militant group.