The FBI is now investigating a group of 17 Middle Eastern men camping in the Mojave Desert who were briefly detained on Easter Sunday, then released, after a 911 phone call was made to the Victor Valley Sheriff’s Station alleging that they had fired over 100 shots in the area.

“They were up all night chanting ‘Allah akbar’-type stuff,” an unidentified police officer was heard saying on an audio recording from a police scanner that was posted online.

(Update: The area is near several military installations, including Edwards Air Force Base.)

According to the local newspaper Victorville Daily Press, a witness hiking in the Deep Creek Hot Springs region that same day described what he saw:

I was about 50 feet away from the hot tub and saw them fire about six to eight shots. I could see them near the hot tubs talking and shooting. I said, “I’m out of here, these guys are crazy,” and decided to leave. As I started heading up the trail I could see them shooting through the canyons. They were shooting toward the hills where people were camping.

Officials say the men were cooperative as they were detained and searched after a helicopter was able to locate them from up above. On Monday, San Bernardino County Sheriff’s Department spokeswoman Jodi Miller reportedly said in an interview with the Los Angeles Times that none of the men “interviewed yesterday were identified as terrorists” and noted that they were cooperative with deputies.

The local CBS News affiliate in Los Angeles reports that several handguns, a rifle, and a shotgun were found on the men, several of which were described on the police scanner as wearing turbans.

However, a records check found all the weapons were registered with the exception of the single rifle, which reportedly did not have a serial number because it was purchased in parts.

Two images showing the detained men were posted to a chat forum and were later picked up by Russian state-run outlet RT.

The group of men were eventually released because they reportedly had no outstanding warrants or criminal records and there was no evidence that a crime had been committed. However, the FBI is reportedly working with local authorities to determine if any crimes were committed.

The area the men were in encompasses San Bernardino County, where the devastating December 2 terrorist attack took place.

On Monday, the FBI announced that they were able to successfully crack the iPhone used by Syed Rizwan Farook, the radical Islamic terrorist who carried out the mass shooting with his Pakistani-born wife Tashfeen Malik. The terrorist attack left 14 dead and 22 wounded.

An Israeli firm’s technology was used to break the iPhone’s supposedly unbreakable encryption.