ISTANBUL (Reuters) – Turkish warplanes struck 15 targets in the al Bab area of northern Syria on Sunday in an operation with Syrian rebels to drive Islamic State (IS) militants out of the border region, the Turkish military said on Monday.

President Tayyip Erdogan has said seizing control of al Bab, around 30 km (19 miles) south of the border, is a goal of the operation before targeting Manbij, from which Kurdish-led forces recently drove IS, and the IS stronghold of Raqqa.

Ten Islamic State defensive positions, command centres and an ammunition store were destroyed in the strikes, the army said in a statement. Nine Syrian rebels were killed and 52 wounded during clashes in the region, it added.

The Turkish military launched the operation, dubbed ‘Euphrates Shield’, on Aug. 24 and the rebel forces have so far seized control of about 1,620 square km (625 square miles) of territory, the military said.

The operation has also targeted the Kurdish YPG militia in the region and 10 of the group’s fighters were ‘neutralised’ in shelling over the last 24 hours as they tried to seize control of the Tal Jijan area, the statement said.

The YPG is an ally of the United States in its fight against Islamic State. Ankara denounces the YPG as an affiliate of the PKK, which has fought the Turkish military in southeast Turkey for three decades and which is designated as a terrorist group by Turkey, the United States and the European Union.