Sirens sounded in Minot, N.D., Wednesday as water from the Souris River topped dikes protecting the city and residents were told to evacuate immediately.


City officials had moved up the evacuation deadline before the early afternoon breach, the Minot Daily News reported. About 11,000 people living in low-lying neighborhoods who had been told they could remain in their homes until 10 p.m. were urged to grab their valuables and leave.

Local officials posted a notice on the city Web site and emergency workers knocked on doors, The New York Times said.

"They are virtually certain that the levee system is going to be overtopped and there's nothing they can do about it," Pat Slattery of the National Weather Service said.

In the Bismarck, N.D., area, the Missouri River flooded parts of Burleigh and Morton counties. Police said they were dealing with daredevils attempting to boat through flooded neighborhoods, The Bismarck Tribune said.

Farther downstream, the U.S. Army Corps of Engineers said heavy rain in South Dakota was forcing it to release more water from the Gavins Point Dam, the Omaha World-Herald reported. That is expected to add up to a foot to the river level at Sioux City, Iowa, and 3.6 inches to 4.8 inches between Omaha, where the river is now 5 feet above flood stage, and Rulo, Neb.

"This continues to be a very dynamic situation and dangerous at the same time," Brig. Gen. John McMahon said. "People along the river are encouraged to make evacuation plans to protect their possessions and property.''

The higher releases from the dam are to continue into August.