Taliban forces entered Afghanistan’s capital city of Kabul on Sunday, effectively taking control of the country following the capture of one provincial city after another over recent weeks.

Afghan President Ashraf Ghani left the country on Sunday evening, as the Taliban entered the presidential palace and declared the war “over.” Ghani said he fled the country to avoid bloodshed.

It marks a stunning end to the two-decade Western campaign in which U.S. and coalition forces sought to transform the country.

The rapidly evolving situation has forced hundreds of thousands of people to flee their homes. There were chaotic scenes at Hamid Karzai International Airport Monday as Afghans and foreign nationals fearing a return to Taliban rule desperately sought to escape the country.

The United Nations has cited continued reports of serious human rights abuses and violations in the communities most affected by the fighting. International aid groups have warned of an imminent humanitarian crisis.

U.N. Secretary-General Antonio Guterres on Sunday expressed particular concern about the future of women and girls in the country, saying hard-won rights “must be protected” and “all abuses must stop.”