Authorities in Texas said on Monday that they have thwarted a "mass casualty attack" after arresting a suspect who allegedly made terroristic threats against police officers.

Seth "Andrea" Gregori was arrested on a terroristic threats warrant Monday morning, the Corpus Christi Police Department said.

"The Federal Bureau of Investigation was notified of Gregori making terroristic threats against Corpus Christi Police Department Officers," the police department said in a statement. "The Federal Bureau of Investigation investigated the threats and secured an arrest warrant for Gregori."

The 21-year-old suspect allegedly planned an attack on police "similar to the 2016 Dallas ambush," the FBI's Houston office said.

In the 2016 incident referenced by the FBI, five Dallas police officers were killed and seven injured in an ambush-style shooting.

The shooter, Micah Xavier Johnson, told a hostage negotiator that he wanted to kill white people, especially police officers, and expressed anger for Black Lives Matter, police said. The ex-U.S. Army reservist was killed by police when they detonated a bomb delivered by a robot.

Police did not release any additional details on the case involving Gregori.

No charges have been filed yet in the case, the Nueces County District Attorney's Office told ABC Corpus Christi affiliate KIII.

It is unclear if Gregori has an attorney at this time.