ST. LOUIS (AP) — Bomb-sniffing dogs are checking an American Airlines plane that was diverted to Lambert Airport in St. Louis.

Lambert Airport spokesman Jeff Lea says Flight 534 left Columbus, Ohio, and was heading for Phoenix. It landed in St. Louis around 8:10 a.m.

American Airlines said in an emailed statement that it requested the security check "out of an abundance of caution."

Lea and the airline provided no information on what prompted the search.

Angie Tabor, spokeswoman for John Glenn International Airport in Columbus, says the FBI is investigating.

The 113 passengers and five crew were taken by bus to the terminal.

Lea says the plane remains on the runway and that it's not clear when it will be allowed to take off.