The "Islamic State of Iraq and Syria" (ISIS) has been ousted from Syria's Idlib province after a final group of the extremist fighters surrendered to rival alliance Tahrir al-Sham and other opposition groups on Tuesday (February 13th), AFP reported.

Some 400 people including ISIS fighters, relatives and wounded, gave themselves up to an alliance of hardline opposition groups on Tuesday, said a spokesman for the Jaish al-Nasr faction which took part in the operation.

"We hit them with artillery in the town of al-Khowein until they agreed to surrender," Abu al-Majd al-Homsi said.

Al-Homsi said the fighters would be interrogated to find out whether they had planted sleeper cells in the area, and would be put on trial in "special courts".

ISIS once held swathes of northern and central Syria including parts of Hama, Homs and Aleppo provinces and much of al-Raqa.

After a string of major defeats last year, hundreds of ISIS fighters fled to a pocket of territory at the intersection of Hama, Idlib and Aleppo provinces.

They have now been fully ousted from all three, according to the Syrian Observatory for Human Rights.

Syrian government troops pushed them out of Hama and into Idlib province last week, Observatory head Rami Abdel Rahman said.