Islamic State militants have seized another town in Iraq’s western Anbar province less than a week after capturing the provincial capital, a tribal leader said Friday, while in neighboring Syria the group’s fighters killed dozens of pro-government forces in the ancient town of Palmyra.

Islamic State fighters combed Palmyra, detaining and killing dozens of people two days after seizing the town, which is home to one of the Middle East’s most famous archaeological sites, activists and officials said.

Maamoun Abdulkarim, the head of the Antiquities and Museum Department in the Syrian capital Damascus, said no gunmen were seen in the area of Palmyra’s 2,000-year-old ruins, which once attracted thousands of tourists.

The Britain-based Syrian Observatory for Human Rights said IS fighters have killed 17 men in Palmyra and that it has unconfirmed reports of the killing of dozens more.

Gov. Talal Barazi of the central province of Homs, which includes Palmyra, said that IS fighters have abducted men and “might have committed massacres.”

An amateur video posted on a pro-IS Facebook page showed people and militants gathering around two bloodied men in military uniforms in a Palmyra street. “Let all the residents see them,” one of the men in the gathering tells an IS fighter.

The video appeared genuine and corresponded to other AP reporting of the events.

Report filed by The Associated Press