Four Turkish soldiers were wounded by artillery fire and rockets fired by Kurdish fighters at their bases in northern Syria, prompting a retaliatory attack by Ankara, the Turkish government said on Sunday.

The Ministry of Defense claimed responsibility for the attacks against Turkish rebels on the Kurdistan Workers’ Party (PKK) and the People’s Protection Forces (YPG), the Syrian Kurdish militia that is a key component of the Syrian Democratic Forces (SDF), an organization backed by from the USA..

Turkey has carried out several military operations in northern Syria in recent years and has dozens of bases in the region.

The four soldiers were taken to a hospital. “There is an adequate response to the terrorists, with strong attacks on the targets,” the ministry added.

Earlier yesterday, Turkish President Recep Tayyip Erdogan said in a campaign speech that Turkey “will never be safe as long as there is an armed terrorist organization” in northern Syria and Iraq. “We hope, in our next term, to intensify our efforts in this direction,” he added, referring to the elections to be held on May 14.