Iraq on Thursday condemned Turkey for sending ground troops onto its territory in pursuit of Kurdish rebels, calling it a "clear violation" of its sovereignty.

"The foreign ministry expresses its condemnation of the incursion of a number of Turkish military units inside Iraqi territory," spokesman Ahmed Jamal said in a statement.

"It represents a clear violation of Iraqi sovereignty and a clear offence to bilateral relations between the two countries," he said.

Turkish special forces entered Iraq on Tuesday in what officials termed a "short-term" incursion in pursuit of fighters from the Kurdistan Workers' Party (PKK) allegedly involved in attacks that killed more than two dozen soldiers and police.

The PKK took up arms in 1984 with the aim of establishing an independent state for Turkey's Kurdish minority, although lately its demands have focused on greater autonomy and cultural rights.

The PKK and Turkish forces are again trading attacks on the ground and from the air, upending a 2013 ceasefire between the two sides.