An attack by Islamic State militants on a military base in northern Iraq shows Turkey’s decision to deploy troops there was justified, Turkish President Tayyip Erdogan said on Friday.

Erdogan told reporters in Istanbul that 18 Islamic State militants were killed but no Turkish soldiers were harmed in the attack at the Bashiqa base in Iraq’s Nineveh province.

Turkey deployed a force protection unit of around 150 troops last month citing heightened security risks near Bashiqa, where its troops are training an Iraqi militia to fight Islamic State, and stirring a diplomatic row.

Erdogan said the problems at the base arose in the wake of tensions between Russia and Turkey, and said that Turkey was acting in line with international law.