The Syrian army says it has fully retaken Aleppo

The Syrian army announced on Thursday that the country's second city Aleppo has been fully recaptured from rebel fighters, the government's biggest victory in the nearly six-year civil war.

"Thanks to the blood of our martyrs and the sacrifices of our valiant armed forces as well as allied forces … the general command of the armed forces announces the return of security to Aleppo after its release from terrorism and terrorists, and the departure of those who stayed there," the army said in a statement.

The announcement came shortly after state television reported that the last convoy carrying rebels and civilians had left eastern Aleppo.

"The last four buses carrying terrorists and their families arrived in Ramussa," a district south of Aleppo controlled by government forces, the channel said.

Ahmed Qorra Ali, an official with the rebel group Ahrar al-Sham, confirmed that "the last convoy has left the rebel-controlled area."

Earlier, the Red Cross said that more than 4,000 fighters had left rebel-held areas of the city in the "last stages" of the evacuation.

The United Nations said it had deployed observers to monitor the final evacuations, under a Security Council resolution adopted on Monday.

Rebel forces, who seized control of east Aleppo in 2012, agreed to withdraw from the bastion after a month-long army offensive that drove them from more than 90 percent of their former territory.

The evacuation agreement was brokered by Russia, which launched air strikes in support of Assad's regime last year, and Turkey, which has supported some rebel groups.