However, many of the tens of thousands of Arab residents — namely those tribes that allegedly took part in the expulsion of the local Kurdish population in 2013 — who fled the advancing Kurdish force have not returned, for fear of retribution from the YPG. There were reports that Kurds were forcibly removing the local Arab population, but the accusations were rejected by the United Nations. According to the Washington Post, Kurds were kurdifying the city after capturing it from the Islamic State of Iraq and the Levant (ISIL), which resulted in tensions. The journal states: After the capture of Tell Abyad by the YPG from ISIL in June 2015, the Tell Abyad canton was proclaimed on 21 October 2015. It was included into the de facto autonomous North East Syria declared by a council including representatives of local Arab, Kurdish, Turkmen and Armenian communities. The 178-member higher council that governed Tell Abyad, elected mixed-gender co-mayors, as mandated under Rojava rules. The elected co-mayors were ethnic Arab Mansour Seloum (later elected co-chairperson for the executive committee to organize a new constitution for Rojava, and replaced by ethnic Arab Hamdan al-Abad) and ethnic Kurd Layla Mohammed. The latter was 27 years old and the first female mayor of Tell Abyad ever. On 27 February 2016, Tell Abyad came under attack from ISIL militants. YPG militias and Asayish police forces repelled the attack and eliminated all of the ISIL militants, but more than 40 security forces and around 20 civilians were left dead. A YPG spokesman claimed that ISIL militants had crossed from Turkey to attack the town. Turkey quickly denied this claim. According to the Syrian Observatory for Human Rights, there was not any infiltration from the Turkish border but dormant IS sleeper cells and others entered the town on the eve of the offensive dressed in YPG uniforms. There have been multiple other instances of ISIL terror attacks in Tell Abyad, for example on 29 June and 8 July 2016 two bombings that each claimed ten civilian lives. On 15 September 2016, the flag of the United States was raised over several public institutional buildings in Tell Abyad. The United States Department of Defense confirmed that U.S. Special Operation Forces were flying U.S. flags in the town of Tell Abyad to deter Turkish harassment shelling or attacks against Syrian Democratic Forces there. Notwithstanding, the Turkish military shelled the area on 22 September. During their control of the city, the Kurdish YPG forces were accused of several serious human rights violations.