A former teacher and his twin brother have been arrested in New York City in connection with a terrorism investigation in which bomb-making materials were recovered, authorities said.

FBI agents and NYPD officers arrested Tyler Toro and Christian Toro, 27, in the Pelham Parkway section of the Bronx Thursday morning.

The two appeared before a federal judge in Lower Manhattan where they were arraigned on federal explosives-related charges.

According to the criminal complaint, law enforcement officials have been monitoring Christian Toro’s activities for months and decided to move in Thursday in the wake of recent events.

Inside the brothers’ Bronx apartment, investigators found low-level components that could be used to make a crude explosive device.

Christian Toro was a teacher at Democracy Prep in Harlem. On January 9th, Toro resigned.