(CNN) -- The Syrian regime says it has taken full control of Aleppo, state-run media announced Thursday, marking a major turning point in the nation's five-year civil war.

Syrian government forces and their allies are now in control of eastern Aleppo, ending more than four years of rebel rule in the area.

The government made significant territorial gains in eastern Aleppo after forces backed by airstrikes entered rebel-held areas in late November.

An estimated 400,000 Syrians have been killed and more than 4.81 million have fled the country since the war began in 2011, according to the United Nations.