Authorities uncovered a potentially deadly school attack plot and have charged two high school students with conspiracy to commit capital murder, officials said Monday.

The boys were arrested Thursday, said Detective John Foster, Williamson County Sheriff's Department spokesman.

Foster declined to discuss specifics on the McNeil High School students' plan. He would not say how police and school officials learned of the plot but added that "we were very fortunate to discover this before it did happen."

"It jeopardized the lives of people there at the school; students and teachers," Foster said. "There were no specific targets other than the school and its occupants."

JoyLynn Occhiuzzi, a Round Rock Independent School District spokeswoman, would not reveal the students' ages or grades, saying only that both were juveniles, which in Texas means younger than 17.

McNeil High has about 2,700 students and 200 staff members. Round Rock is about 15 miles north of Austin.