Three Dutch members of the infamous motorbike gang No Surrender have gone to Iraq to help fight ISIL, a fellow biker says.

Klass Otto told Dutch media the men left for northern Iraq to help Kurds after being horrified by news of ISIL atrocities, the BBC reports.

Syrian refugees are seen at a refugee camp after they fled from ISIL violence. (AAP)

“They are trained guys with lots of experience – with foreign missions too,” Mr Otto said.

“They are extremely disciplined. They don’t drink any alcohol, not even on club evenings.

“They wanted to do something when they saw the pictures of the beheadings.”

Three members of No Surrender have reportedly joined the fight against ISIL. (Facebook)

Dutch prosecutors reportedly said the men were not breaking the law by fighting on the Kurdish side.

He said joining organisations like ISIL was banned, but joining a foreign armed force was not forbidden.

There is also reportedly no evidence the bikers are involved in the fighting or that they have joined a terrorist group.

Members of the Amsterdam chapter of the No Surrender motorcycle club. (Facebook)

The Netherlands’ defence ministry said it could not be held responsible for the actions of ex-servicemen.

ISIL militants. (AAP) (AAP)