(CNN) -- A 25-year-old Florida man intended to use explosives and weapons "to create mayhem'" in Tampa -- a plot that authorities say was foiled thanks to the local Muslim community and law enforcement -- a U.S. attorney said Monday.
"When a person's got an AK-47 which he believes is operable, when he has explosives which he believes are real, and when he has an explosive pack and a car bomb which ... he is going to utilize against Americans, that makes it a crime," Robert O'Neill, U.S. attorney for the Middle District of Florida, told reporters. "Was it real? It was very real."
O'Neill spoke Monday in Tampa after an afternoon hearing for Sami Osmakac on one count of attempted use of a weapon of mass destruction.
The 25-year-old naturalized American born in Kosovo planned a car bombing that would be followed by hostage-taking and the explosion of a suicide belt he planned to wear, according to a criminal complaint made public Monday.
"We all have to die, so why not die the Islamic way?" Osmakac allegedly told an undercover FBI employee, according to the complaint.
Osmakac said in a martyrdom video message recorded shortly before his arrest Saturday night that he wanted "'pay back' for wrongs he felt were done to Muslims," the complaint said.
O'Neill said that, through the local Muslim community, "we were able to know that this person had this ideology and wanted to commit a crime." Steve Ibison, who heads the FBI's Tampa office, called assistance from members of the Muslim community "very significant" throughout the investigation.
"This case is not about the Muslim religion, and it's not about the Muslim community," Ibison said. "It's about an individual who committed a crime."
Two law enforcement officials, who asked not to be identified because they were not authorized to talk about the probe, said the suspect does not appear to have any ties to al Qaeda, and early information indicated he was "self-radicalized."
"I don't have any indication anyone else was involved in the plot and pushing this," one official said.
"There is no indication he was acting at the control or direction of al Qaeda," a second official said.
The federal investigation of Osmakac began in September when a "confidential human source" told the FBI that Osmakac, a resident of Pinellas Park, Florida, "asked for al Qaeda flags," the complaint said.
By November, the suspect was discussing potential terror targets in Tampa and asked for the confidential source's help in getting guns and explosives for the attacks, the complaint said.
The government's source introduced Osmakac to an undercover FBI employee, which led to a December 21 meeting during which the suspect said "he wished to acquire an AK-47-style machine gun, Uzi submachine guns, high capacity magazines, grenades and an explosive belt," the complaint said. He later allegedly gave the FBI employee a $500 down payment for the weapons, according to the document.
"The explosives and firearms that he allegedly sought and attempted to use were rendered inoperable by law enforcement and posed no threat to the public," the government said.
Osmakac outlined his plans during a New Year's Day meeting with the undercover FBI employee, it said. His alleged bomb targets were "night clubs in the Ybor City area of Tampa, the operations center of the Hillsborough County Sheriff's Office in Ybor City and a business in the South Tampa area," the government said.
By Saturday night, however, his primary target was an Irish bar in south Tampa, according to one of the law enforcement officials who spoke to CNN.
Osmakac was looking for places where there would be large crowds, the official said.
After the car bombing, he planned to retrieve guns and explosives stashed in a Tampa hotel room so he could begin the second phase of his attacks, the complaint said.
He told the FBI employee that "he wanted to use the explosive belt to 'get in somewhere where there's a lot of people' and take hostages," the complaint said. He would then demand that the FBI "release some prisoners," it said.
"Once I have this ... they can take me in five million pieces," he allegedly said, "an apparent reference to the explosive belt that would be attached to his waist," according to the government.
FBI agents arrested Osmakac on Saturday night, just after he made the video explaining his motives, the complaint said.
"We arrested him when the attack was imminent," O'Neill said.
The U.S. attorney acknowledged that there might have been significant bloodshed were it not for the tips from local Muslims and the work of law enforcement.
"There was no real danger to the community once we got involved, because we knew we could handle the situation," O'Neill said.
CNN's Carol Cratty and Alan Duke contributed to this report.