Human remains, apparently buried for some time, have been found by construction workers digging on the University of North Dakota campus.

Police said how long the bones had been there wasn't known, and the school said it had been a period of time. Police and university anthropologists are investigating the site, near a school auditorium and the yard of the school president's house.

"This type of excavation is an extremely time-consuming process," Police Chief Duane Czapiewski said. "It's very slow and very deliberate, so we may not know for some time as to exactly what is there."

The contract workers were digging a steam heat line for a new alumni center when they found the bones Wednesday afternoon.

Freshman Scott Eul, 19, said he hoped the remains were not recent. "It's really scary. If it is a dead person, I hope it's from a long time ago," he said.