A 23-year-old Florida man was charged Tuesday with plotting to detonate a backpack bomb at a public beach. Harlem Suarez, also known as Almlak Benitez, was allegedly inspired by the Islamic State group, the U.S. Department of Justice said, in a statement released Tuesday.

The Key West resident “knowingly attempted to use a weapon of mass destruction -- a backpack bomb -- in the United States,” John P. Carlin, assistant attorney general for national security, said in the statement.

Suarez caught the attention of the FBI in April following a series of Facebook posts containing “extremist rhetoric,” including several beheading videos. According to the FBI, Suarez had already purchased components for a “timer bomb” that could be remotely detonated by a cellphone.

“I can go to the beach at night time ... put the thing in the sand ... cover it up ... so the next day I just call and the thing is gonna, is gonna make ... a real hard noise from nowhere,” Suarez told a confidential FBI source earlier in July, according to a criminal complaint filed by the FBI. He was arrested on Monday after he took possession of an inert explosive device.

“Suarez also discussed putting bombs under police cars, in front of police officers’ homes, and possibly purchasing a vehicle and building a car bomb,” the FBI said in the complaint.

Over the last few months, several people have been arrested and charged in the U.S. for either planning to travel to Syria to join the ranks of ISIS, or for plotting to carry out ISIS-inspired attacks on U.S. soil.

In June, three people, including a 20-year-old student in Queens, New York, were arrested and charged with conspiracy to provide material support to the Sunni militant group. In May, two California residents attempting to travel to Syria to join ISIS were arrested by the FBI’s Joint Terrorism Task Force.

According to some estimates, about 20,000 foreign fighters from 90 countries, including nearly 150 Americans, are believed to be fighting alongside ISIS in Iraq and Syria, creating what has been described by the U.S. the “largest convergence of Islamist terrorists in world history.”