But they also aimed to block the advance of Syria's US-backed Kurdish militia.

Dubbed "Euphrates Shield," this marks the first time a foreign state has officially sent ground troops to support Syria's armed opposition in the fight against the extremist group. The Syrian government condemned the offensive.

By evening local time, media outlets reported the anti-ISIS fighters are claiming the operation was a success, but no official confirmation has been made.

The move is aimed at "clearing the Turkish borders of terrorist groups, helping to enhance border security and supporting the territorial integrity of Syria," according to Turkey's semi-official Anadolu news agency.