Police swarmed a high school campus Monday after a 911 call about armed teenagers who turned out to be students re-enacting war scenes with camouflage and mock rifles for an art project.

Summit High School was locked down for about 30 minutes while police sorted it all out.

"We had a little bit of a misunderstanding this morning," said Terry Morawski, director of communications for the Mansfield Independent School District. "I don't know that I can fault anyone involved, but the timing was definitely questionable."

The students were photographing themselves re-enacting scenes from the Vietnam War as part of a project, but with nerves on edge over the fifth anniversary of the Sept. 11 terrorist attacks, a driver who spotted the mock rifles called police.

Summit High School, about 20 miles southeast of Fort Worth, has about 2,800 students.