Five Twin Cities men accused of plotting to go to fight alongside ISIL in Syria are asking a federal judge to drop murder conspiracy charges on grounds that they have “combatant immunity” under both common and international law.

They say combatants are immune from criminal prosecutions for acts of war, including murder, against military targets.

The five — Hamza Ahmed, brothers Adnan and Mohamed Farah, Abdirahman Daud and Guled Omar — are scheduled to appear in federal court in Minneapolis next week for a hearing on that and other motions in the case, which is set to go to trial May 9.

The men were charged last year with conspiring to leave the United States to fight with the Islamic State in Iraq and the Levant (ISIL). In October, the government filed a new indictment that added a charge of conspiracy to commit murder, which attorneys for the men say should not apply.

“ISIL has engaged in atrocious acts,” attorneys for the five said in one motion. “But however one might describe it as an entity, it has an organized professional army engaged in traditional military warfare — an army with which the defendants are alleged to have intended to join in ‘combat.’ ”

Federal prosecutors who brought the case argued in a court filing last month that the men were “grossly mistaken” in claiming ISIL fighters are combatants as part of a regularly constituted military force.

The government considers ISIL a terrorist organization that does not meet the criteria “set forth in the Geneva Conventions by which a regular army is known,” the prosecutors said. That includes being commanded by a person responsible for his subordinates, wearing a distinctive uniform, openly carrying arms and conducting operations in accordance with the laws and customs of war.

Prosecutors also wrote that the current fighting in Syria has been determined a noninternational armed conflict — a battle between a nation-state and an insurgent group or between two rebel groups within the borders of a single country — which would invalidate any claims of combatant immunity. And even if the fighting in Syria were considered an international armed conflict, they said, the men can’t be considered combatants anyway.

“They are, if they must be categorized within the international law of armed conflict, best categorized as aspiring war criminals,” the prosecution said.

In a reply filed this week, the defendants called that categorization “an incendiary claim that is without factual or legal support.” They also argued that nothing in the government’s evidence indicates any intent to target innocent civilians abroad or commit suicide bombings or beheadings.

The attorneys maintain that the insurgency in Iraq and Syria has evolved into an international conflict in which the U.S., Britain, France and other countries are involved. Not calling it so, they say, “does violence to the English language.” ISIL is more than just a terror organization, they said, but now a “full-blown government.”

Two other defendants caught up in the federal probe, Zacharia Abdurahman and Hanad Musse, pleaded guilty in September to conspiracy to provide material support to a terrorist organization. Another, Abdullahi Yusuf, pleaded guilty to conspiracy in February and agreed to testify for the government. A 10th man, Abdirizak Warsame, was indicted in December.

Twitter: @smontemayor