A U.S. Army veteran has been arrested for an attempted terror attack in “multiple” Los Angeles locations allegedly in “retribution” for the mosque mass shooting in New Zealand last month, federal prosecutors announced Monday.

Mark Domingo, a 26-year-old former U.S. Army infantryman who served in Afghanistan, was charged with providing and attempting to provide material support to terrorists in his attempt to make an improvised explosive device (IED) “in order to commit mass murder,” according to an U.S. District court indictment filed over the weekend.

The California man was arrested Friday night after receiving what he thought was a live bomb to carry out his attack but was, in fact, a fake explosive delivered by an undercover law-enforcement officer as part of an FBI investigation.

According to the complaint, Domingo was outraged over the massacre at two New Zealand mosques that killed 50 people and injured dozens on March 14, and he boasted in online posts about purchasing supplies to make several bombs.

“There were mosque shootings in New Zealand,” Domingo posted to a private online chat on March 14, according to federal prosecutors. “[T]here must be retribution.”

He added: “I feel like I should make a christians life miserable tomorrow for our fallen bros n sis in [N]ew Zealand...maybe a jews life...they shed our blood...no Muslim should have to experience this, a message needs to be sent.”

In various conversations with an FBI informant who was already in the private message group and an FBI “online covert employee” two days later, Domingo expressed support for a violent jihad, the indictment claimed.

For six weeks, Domingo plotted with the informant about murdering several “enemies,” including Christians, Jews, white supremacists, LAPD police officers, even his next-door neighbor. He also allegedly discussed his desire to set off explosives on the Santa Monica Pier and on several Los Angeles freeways, and voiced support for ISIS—though he had trouble developing a concrete plan.

In one exchange, the informant asked Domingo if he intended to get caught, to which he replied: “Martyrdom, bro,” Domingo said, according to the indictment.

Finally, the 26-year-old “asked his confederate… to find a bomb-maker,” revealing he had “purchased several hundred nails to be used as shrapnel inside the IED.”

“Domingo said he specifically bought three-inch nails because they would be long enough to penetrate the human body and puncture internal organs,” the complaint stated. Domingo also allegedly showed up to one meeting with the informant, armed with a rifle similar to an AK-47.

The 26-year-old, who completed a four-month deployment to Afghanistan in Jan. 2013, was finally arrested after he told the informant of his plans to attack a “white-nationalist rally” in Huntington Beach on April 27.

“This investigation successfully disrupted a very real threat posed by a trained combat soldier who repeatedly stated he wanted to cause the maximum number of casualties,” U.S. Attorney Nick Hanna said on Monday in news conference announcing the “chilling terrorism plot.”

Domingo, who has been in federal custody since his arrest, is expected to appear in court Monday afternoon.