The International Organization for Migration (IOM) said that a total of 4,129 illegal migrants have been rescued and returned to Libya so far in 2021.
The rescued migrants comprised 293 women and 215 children, Xinhua news agency quoted the IOM as saying on Monday.
It added that 73 migrants died and 159 others went missing on the Central Mediterranean route so far this year.
A total of 11,891 illegal migrants were rescued and returned to Libya in 2020, according to IOM estimates.
At least 381 migrants died and 597 went missing on the Central Mediterranean route during the year.
Due to the insecurity and chaos in the North African nation following the fall of its leader Muammar Gaddafi in 2011, thousands of illegal immigrants, mostly Africans, chose to cross the Mediterranean from Libya towards Europe.
Many illegal migrants were either rescued at sea or arrested by the authorities, and detained inside overcrowded reception centres in Libya, despite repeated international calls to close them.