Islamic State (Isis) jihadis have launched a suspected chemical attack against Kurdish fighters in northern Iraq, Kurdish authorities said. Dozens of Peshmerga militants and civilians suffered from vomiting, dizziness and difficulty breathing after improvised rockets struck an area south of Sinjar, a north west town about 50km from the Syrian border, according to the Kurdistan Region Security Council (KRSC).

The authority said victims of the missile attack, which it blamed on IS (Daesh), were receiving medical treatment, adding it sought the help of the international coalition against the jihadi group to investigate the incident. "We believe it was chlorine," a KRSC official speaking on condition of anonymity told IBTimes UK, adding no one was killed.

Sinjar became infamous for the massacre of the local Yazidi ethnic minority at the hands of IS militants after it was overran in 2014. The town was liberated by Kurdish Peshmerga fighters with the help of Yazidi forces in a highly symbolic victory in November 2015.

The Kurds have since fortified their positions in the area, bringing fighting to a temporary stalemate. "[IS] know they can't break through the frontline and [have to] resort to these type of attacks," the KRSC official said.

If confirmed, it would be the eighth time IS has deployed chemical weapons against the Peshmerga. Earlier in February, tests by Organisation for the Prohibition of Chemical Weapons (OPCW) found that the extremist group targeted Kurdish militias with mustard gas south west of Erbil in August 2015.

The jihadis are also known to have used chlorine-based chemical to fill roadside bombs, IEDs and mortar shells in the past.