YAZOO CITY, Miss. -- An Amtrak passenger train derailed in rural central Mississippi late Tuesday, killing at least one person on board and injuring as many as 70.

The 10-car train, traveling from New Orleans to Chicago, toppled onto its side about 25 miles north of Jackson, authorities said.

"We have one confirmed dead," said Amy Carruth, a spokeswoman for the Mississippi Emergency Management Agency in Jackson.

"We understand some of the injured are possibly critical."

Lee Stokes, also of MEMA, said that while the derailment was believed to be an accident, the FBI had sent agents to the scene. Gov. Haley Barbour declared a state of emergency.

The train appeared to leave the track in an elevated area and landed on its side several feet below the track surface. The train had an engine and nine cars, and most of the cars derailed.

Stokes said it appeared about 65 people suffered "minor to critical injuries." She said the injured were initially treated at emergency stations, then moved to hospitals.

At least four Jackson-area hospitals received injured, including two very critical patients taken by helicopter to the University of Mississippi Medical Center.

Dr. Bob Galli, head of the UMC trauma center, said the two were Amtrak employees -- a 38-year-old female and a 43-year-old male.

Jim Pollard of American Medical Response, an area ambulance service, reported two passengers in critical condition, three others identified as serious and 52 reported with less than serious injuries.

Dan Stessel, a spokesman for Amtrak, said the train's manifest showed 72 passengers and a 12 crew members but that a review indicated perhaps only 68 passengers were on the train.

Carruth said her agency "was sending every resource we can get our hands on out there. ... At last report we've still got people trapped."

Besides search teams, portable lights and other equipment were being rushed to the scene, she said. Red Cross staffers were on hand to assist passengers.

Yazoo County sheriff's dispatcher Mary Whisenton said at least five ambulances had also been sent to the scene.

Stessel said he had no information on what caused the accident.

Stessel said the train made several stops after leaving New Orleans about 1:55 p.m., including Jackson. He said the train derailed at about 7 p.m., near the Yazoo-Madison county line, before its scheduled stop in Yazoo City.