NEW YORK (CBSNewYork) — A Bronx neighborhood is stunned after learning twin brothers are facing federal charges in connection with an alleged bomb-making plot.

The brothers, Christian and Tyler Toro, were busted by federal authorities in their Pelham Parkway apartment Thursday and neighbors say their arrests kept them up all night.

“We are lucky we are safe. If they are making something and it blows up in the building then what happens?” said resident Farkhanda Rizvi.

READ THE COMPLAINT AGAINST THE TORO BROTHERS

The FBI says the 27-year-old brothers were storing bomb-making materials in their apartment and researching how to assemble the explosives.

“What are they doing? What is their plans?” Rizvi demanded.

But authorities have not yet answered those questions.

The investigation stems from a Democracy Prep Charter High school student being arrested for allegedly calling in a bomb threat on Dec. 4.

The Harlem school was where Christian Toro was a teacher.

On Jan. 10, Toro abruptly resigned. Two days later, his brother, Tyler, returned his school-issued computer and a tech specialist found a copy of “The Explosive Book” downloaded to the computer, officials said. That’s when authorities got involved.

A Democracy Prep High School spokesperson released a statement saying in part, that after Christian Toro resigned, the school “did a routine review of his laptop and was deeply disturbed by suspicious content.”

NYPD Deputy Commissioner of Intelligence and Counter-terrorism John Miller said when they searched the Toro’s Matthews Avenue apartment they found “over 30 pounds of chemicals which mixed together in certain combinations constitute explosive precursor materials.”

Miller said there was even a notecard in a backpack that read, “under the full moon, the small ones will know terror.”

Officials said a diary statement also read “if you’re registered as a sex offender, things will be difficult. But I am here 100 percent living, buying weapons, whatever we need.”

Authorities say Christian Toro was arrested on Jan. 31 for allegedly raping a 15-year-old student.

Students told investigators Toro welcomed them in his apartment and paid them to break apart fireworks and store the powder from them in containers.

Authorities assure residents in the apartment building and all over New York City that there is no threat.

The Toro brothers both pleaded not guilty and are being held until their next court date.