DEVELOPING: Two Bronx Men Arrested in Terror Scheme.

A former Harlem high school teacher and his twin brother were arrested on Thursday in a federal investigation and charged with building an explosive device, according to court papers.

The two men kept boxes full of what the government said were bomb-making materials in a closet in an apartment they shared in the Bronx, according to a criminal complaint filed in Federal District Court in Manhattan.

The teacher, Christian Toro, was arrested on Jan. 31 on charges of raping a minor. The other man was identified as Tyler Toro. The complaint said that a diary found in the apartment contained writing that referred to the brothers as “Twin Toros.” “Strike us now,” they wrote, “we will return with nano-thermite.”

Related: Christian & Tyler Toro: 5 Fast Facts You Need to Know.