DREXEL HILL, PENNSYLVANIA — Pennsylvania police have found more than 1,600 rounds of ammunition and a handgun allegedly belonging to a Taiwanese exchange student who reportedly made violent threats.

The 18-year-old exchange student An Tso Sun, was arrested last week after threatening to "shoot up" Monsignor Bonner & Archbishop Prendergast Catholic High School in Drexel Hill, Pennsylvania.

In the latest investigation, local authorities discovered 1,600 bullets for an AR-15, AK-47 and an untraceable handgun that Sun had put together.

According to the police, a black bag with the firearms inside was found in Sun's room by his host family, and they hid it before the police arrived for their initial search.

The student's attorney had said last week that nothing his client had was illegal, and that the student was truly making a joke about wanting to shoot up the school, calling it a misunderstanding.

Upon his arrest, Sun was expelled from the school and remains in jail at Delaware County Jail in lieu of a US$100,000 bail for one count of making terroristic threats. His first hearing will be held on April 11.

Sun's parents arrived in the US on March 31 to help their son with the legal process.