A B-52 bomber crashed and burst into flames early Tuesday on a runway while practicing "touch-and-go" landings at K.I. Sawyer Air Force Base, but all eight crew members apparently survived, officials said.

The plane, normally equipped to carry nuclear bombs, crashed about 1:15 a.m. EST, said Lt. Naomi Siegal, a spokeswoman at the Strategic Air Command installation.No weapons were aboard, said Lt. Col. George Peck, a spokesman for SAC headquarters in Omaha, Neb.

The crew was practicing landings after a seven-hour training flight when it crashed during one of its touch-and-go approaches, Peck said. During such maneuvers, landing gears touch the ground but the plane doesn't land.

"Initial indications were that the aircraft burst into flames upon landing," said Peck. "It had already done a series of landings. . . . "

He said the crew was taken to hospitals.

Members of the crew suffered broken bones, but no one was burned, said Capt. Paul Bicking, a Sawyer spokesman.

It was not known who was at the controls when the plane crashed, Peck said.

Peck said a board of officers will investigate the accident, adding weather did not appear to be a factor in the crash.