Hundreds of Kurdish fighters have arrived in eastern Syria to help the Syrian Democratic Forces (SDF) fight the "Islamic State of Iraq and Syria" (ISIS) after a major setback last week, AFP reported Tuesday (October 30th).

The Arab-Kurd alliance, backed by the international coalition, launched an offensive on September 10th to expel ISIS from their holdout of Hajin on the Iraqi border.

They advanced slowly inside the pocket backed by coalition airstrikes, but faced sand storms and a vicious fightback including suicide bombers, which forced them to retreat back to square one on Sunday.

According to the Syrian Observatory for Human Rights, at least 72 SDF fighters were killed in last week's ISIS counter-attack.

The monitoring group said hundreds of Kurdish fighters, men and women, had arrived on the outskirts of the Hajin pocket since then.

"Since Sunday, over two days, 500 fighters from the Kurdish special forces, the People's Protection Units and the Women's Protection Units have been sent," Observatory chief Rami Abdel Rahman said.

Several thousand SDF fighters were already present in the area, he said.