OAKLAND, Calif. -- An 8-year-old boy watching the Oakland Athletics' game against Tampa Bay on Tuesday night suffered burns on one of his legs when another fan tossed an explosive device from the upper deck of the Coliseum.

The boy was taken to a hospital for treatment. No further information was immediately available.

"That was a shame," Devil Rays manager Lou Piniella said. "I saw the kid fall down in the left-field bleachers. It startled everybody."

A suspect was in police custody, the A's said. The device, commonly known as a cherry bomb, made a loud boom as it fell from the third deck to the first tier of bleachers in left field. Players turned to look, causing a short delay during the third inning.

"I thought a bomb went off it was so loud," Tampa Bay center fielder Rocco Baldelli said. "It was shaking."

It was the latest in a string of trouble with fans this season at the Coliseum.

On April 19, a fan threw a cell phone at Texas Rangers outfielder Carl Everett.

The phone was tossed from the second deck of the Coliseum, said David Rinetti, the A's vice president of stadium operations. The person arrested for throwing the phone was intoxicated, he said.

Security was heightened for the following day's game. Rinetti said staffing was increased and a uniformed police officer was stationed at the visitor's bullpen. In addition, an in-house video monitoring system was being used to monitor the right-field area.

Everett was hit four days after umpire Laz Diaz was attacked by a fan at U.S. Cellular field in Chicago during a White Sox-Royals game.

Later in April, a man at an A's game nearly bit off a police officer's pinkie finger when the officer tried to help Coliseum security break up an argument between fans.

In response to the recent fan violence, a bar at the Coliseum was forced to stop serving drinks after the seventh inning of Athletics' games. The West Side Club now follows the same alcohol restrictions already in place in the stands.