CLASHES between Kurdish fighters and Turkey-backed opposition gunmen in northern Syria left at least 18 fighters dead in some of the most intense fighting in weeks, an opposition war monitor and a Kurdish news agency said Tuesday.

Exchanges of fire and shelling between the Kurdish-led Syrian Democratic Forces (SDF) and Turkey-backed opposition gunmen who identify as the Syrian National Army have not been uncommon since Turkish troops invaded parts of northern Syria in October last year.

The clashes began before midnight Monday near the town of Ein Issa and were triggered by an assault from Turkey-backed gunmen on SDF positions, according to the Britain-based Syrian Observatory for Human Rights, an opposition war monitor, and the Kurdish ANHA news agency.

The Observatory said Turkey-backed fighters lost 18 gunmen in the battle and an unknown number of SDF fighters were also killed or wounded.

ANHA said dozens of Turkey-backed fighters were killed or wounded.

An SDF spokesman who goes by the name of Mervan Qamishlo also confirmed the clashes, saying the group’s fighters repelled a Turkey-backed attack.

He did not comment on how many SDF gunmen were killed but said six civilians were wounded in the shelling.

Maj. Youssef al-Hammoud, an official with the Syrian National Army, said the fighting started when SDF fighters attacked their positions on two fronts.

Also in northern Syria, two explosions hit the towns of al-Bab and Afrin that are both controlled by Turkey-backed fighters, according to the Observatory and Thiqa news agency, an activist collective.

(SD-Agencies)