Thousands of Turkish troops have crossed into northern Iraq in their hunt for Kurdistan Workers Party (PKK) guerrillas, a senior military source said on Friday, in an escalation of a conflict that could destabilize the region.

Turkey's military said the land offensive had fighter aircraft in support. Turkish TV said 3,000 to 10,000 soldiers had entered Iraq, though Iraq's foreign minister denied it was a major operation, saying only a few hundred troops were involved.

Thousands of Turkish troops have crossed into northern Iraq in their hunt for Kurdistan Workers Party (PKK) guerrillas, a senior military source said on Friday, in an escalation of a conflict that could destabilize the region.