Police spokesman Sarkawt Ahmed confirmed 13 arrests, but without giving the circumstances.

According to a member of the local teachers' council, Adil Hassan, 14 teachers were arrested at their homes before they were due to join a demonstration outside the regional education ministry that went ahead without them.

Clashes with security forces broke out at a November 19 demonstration in Sulaimaniyah that drew a crowd of more than 5,000 people, also over unpaid wages.

With the autonomous Kurdish region of northern Iraq in financial crisis due to falling oil prices and the costs of battling jihadists, public sector workers in the oil-rich region have staged several protest strikes since last year.