The Iraqi Oil Ministry said it denounced the takeover of two key crude oil production facilities by Kurdish military forces in the north of the country.

"The Ministry of Oil calls on the Kurdish people to understand the seriousness of the situation and directs those responsible for the action to retreat from the oil fields to avoid punishment," the ministry said in a statement Sunday.

Kurdish forces, known as Peshmerga, took control over two key oil facilities in the north of Iraq last week. The seizure comes after Iraqi Prime Minister Nouri al-Maliki accused Kurds of being on the wrong side of the fight against a growing Sunni insurgency.

The ministry said Friday the Kurdish force should fight against Sunni-led insurgents rather than occupying oil fields in the north of Iraq.

In its statement Sunday, the ministry described the seizure as irresponsible and a blatant disregard of threats to national unity.

The Islamic State of Iraq and Syria in June said it took over a key oil refinery in northern Iraq that processes petroleum products for the domestic market. The Iraqi Oil Ministry said the Kurdish force was exploiting the threat for its own gain.

The Kurdish government has exported some oil produced from its territory from a sea port in Turkey. The federal government in Baghdad says the exports are illegal.