ISTANBUL (Reuters) - Turkish warplanes carried out air strikes on the Syrian city of al-Bab held by Islamic State on Friday, the military said in a statement, after four Turkish soldiers were killed in the area over the past two days.

The air strikes shortly before 8 a.m. (0500 GMT) destroyed buildings believed to be used by the radical jihadist group, the military said in a statement. The strikes were part of Turkey’s “Euphrates Shield” operation, launched in August to try to push Islamic State and Kurdish militia fighters from the border.

Prime Minister Binali Yildirim said on Thursday that Turkey would retaliate after three of its soldiers were killed in what the military said was a suspected Syrian air strike. Another soldier was later killed in clashes with Islamic State, the military said earlier on Friday.