KABUL, Nov. 21 (Xinhua) -- More than 464,000 undocumented Afghan refugees have returned from Pakistan, Iran, Turkey and European Union states since the beginning of this year, the United Nations migration agency the International Organization for Migration (IOM) reported Thursday.

Some 439,100 Afghans returned from Iran and Pakistan since Jan. 1, 2019, according to IOM situation update reaching Xinhua on Thursday.

Undocumented Afghan migrants were defined as those Afghan migrants not in possession of documentation issued by the country where they are residing.

In total 420,539 Afghans returned from Iran, including 183,509 Afghan who returned spontaneously while 237,030 were deported.

"Meanwhile, 18,561 Afghans returned from Pakistan in total. 15,995 returned spontaneously, 2,566 were deported," it said.

Up to 1,719 Afghans also returned from European Union countries while 23,789 refugees came back from Turkey over the period.

More than 849,000 Afghan refugees had returned or been deported to Afghanistan in 2018 mainly from neighboring countries, according to official figures from the Afghan Ministry of Refugees and Repatriations.