A Turkish air strike killed at least three people and injured others on Saturday at a camp for displaced people in northern Iraq housing thousands of Kurdish refugees from Turkey, said Rashad Kelani, a Patriotic Union of Kurdistan party official.

The air strike took place three days after Turkish President Tayyip Erdogan warned Iraq that Turkey would "clean up" a refugee camp which it says provides a haven for Kurdish militants.

An Iraqi security official, who spoke on condition of anonymity, confirmed an air strike had killed and injured people in the camp but did not give details.

Turkish forces have stepped up attacks on bases of the outlawed Kurdistan Workers Party (PKK) inside northern Iraq over the last year, focusing their firepower and incursions mainly on a strip of territory up to 30 km (about 20 miles) inside Iraq.