The Arizona Office of Homeland Security said about 1,000 people took part in the drill Sunday morning, which started when a man walked into the Mariposa Port of Entry compound, shouted the name of a mythical terrorist group and set off an explosion. The man was actually a firefighter in a protective suit.
High school drama students played injured and dead victims, complete with makeup depicting burns and other injuries, as several more explosions detonated. A mock toxic gas also was released.
Some 40 U.S. agencies and 20 Mexican agencies were involved in the drill. The exercise ends Tuesday after authorities focus on identifying victims and assessing economic consequences of an attack.
Frank Navarrete, director of Arizona's homeland security office, said it was too early to evaluate the drill's success.
``So far, it's an exercise,'' he said. ``We're going to inject some interesting things that the players don't know yet and we're going to see how they react - and that's really the key.''
Since the Sept. 11, 2001, attacks on New York and Washington, many states have held terror drills, including Florida, South Carolina, New Jersey, Louisiana and Maryland.
In Newark, N.J., on Saturday, a drill simulated what might happen if there was an explosion in a cargo container Port Newark. More than 600 federal, state and local emergency workers participated.
Navarrete said the drills allow local, state and federal authorities to test vital communications equipment. During Sunday's drill, he had difficulty talking to Gov. Janet Napolitano on a hand held-radio.
After struggling to hear one another, Napolitano said, ``That's why we do these things, right?''