Twenty-two Iraqi militants were killed and 15 more injured, on Monday during a suicide bombing training session when an instructor accidentally set off an explosion during a demonstration. The commanders was reportedly training them on the use of explosive belts and car bombs, when of the devices went off

According to the New York Times, the would-be terrorists were part of a group called the Islamic State of Iraq and Syria, or ISIS. The group professes to be battling Iraq's Shi'ite-led army, and has been linked to bombing attacks throughout the country.

Security forces who arrived on the scene after hearing the blast, arrested eight militants who were trying to flee the training site on farmland in northeastern Iraqi province Samara. Per the Associated Press, 12 of the wounded militants and another ten were arrested attempting to leave the area. One Iraqi Army officer told the Times that the instructor responsible was known as an ISIS recruiter, but had managed to "kill the bad guys for once." 

Al-Qaeda recently said it had severed ties with the group because ISIS leader Abu Bakr al-Baghdadi has repeatedly gone against al-Qaeda chief Ayman al-Zawahiri's wishes. ISIS is Iraq's largest Sunni militant group. 

Suicide attacks in Iraq have become more common in recent months. Just last week, a series of car bombs killed at least 16 and wounded more than 120 people around Baghdad.