Turkish airstrikes killed at least 36 pro-regime fighters backing Kurdish militia in Syria’s north-west Kurdish enclave of Afrin on Saturday, a monitoring group said. The Kurdish-led Syrian Democratic Forces alliance said the Turkish raids targeted pro-regime positions, but gave no death toll.

The British-based Syrian Observatory for Human Rights said the strikes on Kafr Janna were the third such raid on loyalist fighters in the enclave bordering Turkey in less than 48 hours. They came after Turkish raids on other parts of the enclave killed 14 pro-regime fighters on Thursday and four more on Friday, the monitor said.

Turkish-led Syrian opposition fighters have advanced steadily since 20 January when they launched an assault on Afrin, controlled by Kurdish YPG units. The Syrian government deployed fighters to the enclave a month later after the Kurds appealed for help.

The Observatory says Turkish-led forces control more than 20% of the enclave after seizing the area of Rajo in the north-west of Afrin on Saturday. They also seized a strategic mountain in the north-east of the enclave, a military official from the Turkish-led operation said.

Ankara says the YPG is a “terrorist” extension of the Kurdistan Workers’ party (PKK), which has waged a three-decade insurgency against the Turkish state. The YPG has been a key component of a United States-backed Kurdish-Arab alliance that has been fighting Islamic State in Syria.

More than 140 civilians have been killed in Turkish bombardment since the start of the assault, but Turkey says it takes the “utmost care” to avoid civilian casualties. Thousands of civilians have fled their homes since the start of the operation, either to Afrin or nearby government-controlled areas.