A vehicle carrying a rocket booster for an unarmed Minuteman III intercontinental ballistic missile tipped over while being transported from the Minot Air Force Base to a launch facility in northwestern North Dakota, the military said.

The Air Force said no one was seriously injured and the public was not in danger.

The vehicle crashed on a gravel road at about 8 a.m. Thursday near Makoti about 70 miles from the base, the Air Force said.

"It rolled on its side and into a ditch," said Maj. Gen. Roger Burg, an Air Force spokesman. "It was preparing to turn, and it appears the wheels got off the edge of the roadway.

"We'll have to determine whether it was a problem with the road, a problem with the driver or a problem with the equipment," Burg said Thursday.

"There was no weapon present and no danger to the public," he said.

Two airmen in the vehicle were not injured except "for a bump here and there," Burg said.

The booster rocket, which is 66 feet long and weighs 75,000 pounds, was being hauled in an enclosed trailer, Burg said. A convoy of security personnel was escorting the truck, he said.

The booster rocket and the transport rig likely will remain in the ditch at least until Friday, he said.

"We have a collection of the best experts we have assessing the situation - we want to make sure we can move it back on its wheels and onto the roadway," Burg said.

It is a routine procedure to transport the boosters to and from the base, and it is not the first time a missile transport vehicle from the base has been involved in a crash, he said.

"We have had three or four similar accidents over the last 25 to 30 years," he said.

The truck tip-over is the latest in a long string of recent incidents at the Minot base, which is the center for 150 Minuteman III missiles, sunk in hardened silos, and is one of two B-52 bomber bases in the country. The base is home to about 4,800 active duty military personnel.

Earlier this month, three ballistic missile crew members from the base fell asleep while holding classified launch code devices. The Air Force said the missile launch codes were outdated and remained secure at all times. But that came after other missteps, including an incident last August in which a B-52 bomber that was mistakenly armed with six nuclear warheads flew from the Minot base to Louisiana.

In May, the Minot Air Force Base's 5th Bomb Wing, which was blamed for the foul-up, came up short in a nuclear weapons handling inspection. It will have to be retested.