Two brothers from Fishers accused of trying to sell manufactured firearms and ship the weapons overseas to the Islamic State group are facing federal charges, authorities said.

A federal grand jury indicted Moyad Dannon, 21, and Mahde Dannon, 20, with firearms offenses and one count of attempting to provide material support and resources, including firearms, to the Islamic State of Iraq and al-Sham, also known as IS, U.S. Attorney Josh Minkler announced Thursday.

The brothers remain in custody and appeared in court for their arraignment Thursday, Minkler said.

Moyad Dannon's attorney, Mario Garcia, told IndyStar that his client is "presumed innocent."

"We look forward to receiving and reviewing whatever evidence the government has based its allegations upon," Garcia said. Mahde Dannon's attorney didn't immediately respond to a request for comment.

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The case is the "first of its kind" for the FBI where individuals are allegedly making guns to sell to IS, according to a news release.

“This indictment paints a vivid picture of the rapid rise of homegrown violent extremism and the lengths people are willing to go to in their support of terrorist activity," said Grant Mendenhall, special agent in charge of the FBI’s Indianapolis Division.

Handed down last week, the indictment came after a months-long investigation that involved the Fishers Police Department. Authorities said the brothers sold a number of "illegally-obtained" firearms between July 2018 and December 2018 to a felon who was cooperating with the FBI. That individual then introduced the brothers to an undercover FBI agent.

Around the same time, officials say the brothers also started manufacturing untraceable "ghost guns" by buying unserialized firearms parts online and assembling those parts into semiautomatic rifles that they allegedly sold to the agent.

In February, the brothers built a fully-automatic rifle that they provided to the agent, Minkler said. Moyad Dannon later accompanied the agent to a location near the southwest border to try to market the rifle to a potential buyer who also was with the FBI, according to authorities.

Moyad Dannon learned during the trip that the potential buyer wanted to ship the weapons to a location in the Middle East, where they'd be used by IS, a designated foreign terrorist organization, the news release said.

But authorities say that didn't deter the brothers from manufacturing and selling at least 55 more "ghost guns" to the southwest buyer.

In May, officials say the brother manufactured five untraceable, fully-automatic rifles and sold the weapons to undercover FBI agents posing as employees of the buyer. They were then arrested by the FBI.

The men face up to 10 years in prison on each of the firearms charges and a maximum of 20 years in prison on the charge of trying to help IS.

Contact IndyStar reporter Crystal Hill at 317-444-6094 or cnhill@gannett.com. Follow her on Twitter: @crysnhill.