The large, mysterious drones reported flying over parts of New Jersey in recent weeks appear to avoid detection by traditional methods such as helicopter and radio, according to a state lawmaker briefed Wednesday by the Department of Homeland Security.

Two Republican Jersey Shore-area congressmen, U.S. Reps. Chris Smith and Jeff Van Drew, have called on the military to shoot down the drones. However, Pentagon spokeswoman Sabrina Singh told reporters Wednesday that “our initial assessment here is that these are not drones or activities coming from a foreign entity or adversary.”