A spokeswoman for ExpressJet Airlines says a Continental Express jet with 53 people on board has made an emergency landing in Oklahoma.

Kristy Nicholas says Flight 2916 diverted to Tulsa International Airport just after 9:30 a.m. Monday after the three-member crew said they were having a "pressurization problem."

Firefighters and ambulances were called to the scene but reported no injuries.

Nicholas says a second plane was flown from Houston to Tulsa to take the 50 passengers on to Omaha. The company's Web site indicates the plane took off shortly after 2:30 p.m.

Nicholas says the original plane is being examined by maintenance personnel to determine what caused the cabin pressure to drop.