VIEQUES, Puerto Rico (AP) _ U.S. fighter jets dropped inert bombs on the Navy's prized firing range on Vieques island Monday, the Navy said, resuming exercises despite protests seeking a halt to training on the island.

The bombing runs began about 2 p.m., said Navy spokeswoman Lt. Cmdr. Katherine Goode. Activists opposed to the exercises had invaded the range and reportedly were hiding there even as the bombing began.

Protest leader Ismael Guadalupe said the bombing posed ``a threat to human life.''

Navy officials, however, said there were no protesters on the bombing range on the eastern tip of the Puerto Rican island.