The U.K.-based Syrian Observatory for Human Rights announced Sunday that 120 civilians had been killed since the start of the Turkish offensive in northern Syria.

The group also said 300,000 civilians had been displaced since the start of “Operation Peace Spring” on Wednesday, Oct. 9.

The offensive began after the withdrawal of U.S. troops who had been supporting a coalition of Syrian Arab and Kurdish fighters against the remnants of the Islamic State militant group. Amid widespread criticism that the U.S. was leaving its majority Kurdish-led allies to fend for themselves, Turkish forces launched an assault on northeastern Syria to remove the Kurdish YPG militia from the region around Turkey’s southern border. Ankara views the YPG and other Kurdish forces as terrorists.

The United Nations estimated over 160,000 people had been forced to flee their homes as of Friday.

Ankara is also seeking to resettle some 3.6 million Syrian refugees currently living in Turkey in a proposed “safe zone” along the Syria-Turkey border.

Last week, Kurdish forces struck an alliance with Russian and Syrian government forces, prompting the latter to send troops into northwestern Syria to protect the Kurds.

A five-day ceasefire was brokered between Kurdish forces and the Turkish military Thursday, though reports of clashes have continued.

The Syrian civil war began in 2011 and is among the world’s deadliest conflicts, with over half a million killed and scores of reported human rights violations including torture and chemical attacks.