KANSAS CITY, Mo. - Residents of the Plains states huddled for cover early Thursday as a major storm system that has killed at least two people moved through the region, bringing heavy snow and tornadoes to some areas.

Severe weather warnings and watches were in effect from South Dakota to Texas, as authorities warned residents to stay alert for tornado warnings.

A husband and wife people were killed Wednesday near Elmwood, Okla., when a storm blew apart their home and a large shed, said Dixie Parker, the Beaver County emergency management director.

Weather spotters tracked a series of tornadoes in sparsely populated western Kansas, but there were no reports of significant damage, sheriff's officials from several counties in the area said.

Severe weather was expected to move east across the state Thursday, but was not expected to be as strong as the storms that hit western Kansas Wednesday, said meteorologist David Beusterien with the National Weather Service in Pleasant Hill, Mo.

At least eleven tornadoes were reported throughout western Nebraska on Wednesday, damaging several homes and farm buildings, emergency management officials said. There were no reported injuries.

A tornado as much as 600-feet wide touched down in Holly, Colo., on Wednesday, damaging homes and injuring at least two people, authorities said.

Chris Sorensen, a spokesman for Prowers County, Colo., emergency management, said it appeared people in the area were generally prepared.

"Residents pay attention to those things and being in a rural area we're familiar with what can happen," he said. "And we always watch the sky."

In Wyoming, a school bus carrying 36 students from Tongue River High School to a competition in Cheyenne in the state's southeast collided with two minivans on snowy Interstate 90 on Wednesday, school officials said.

Soon after, another pileup in the same area involved several passenger vehicles and seven big rigs, two of which were hauling diesel fuel. One of the diesel haulers rolled over and authorities said the other leaked around 1,000 gallons of fuel.

Four people were taken to a hospital, and one injury was considered serious, according to Wyoming Highway Patrol spokesman Sgt. Stephen Townsend. It was not immediately clear which vehicles the injured had been in, but no one on the bus was hurt.

The wintry weather closed a 100-mile stretch of I-90 and 45 miles of I-25. Thirteen other state roads were closed.

At least three people were injured in the Texas Panhandle as storms that brought winds up to 70 mph, hail and rain, spawned several tornadoes.

National Weather Service officials said numerous tornadoes touched down in the Texas Panhandle Wednesday night, including one that was on the ground at Caprock Canyons State Park for about 20 minutes. While many of the tornadoes were in areas so rural that no damage was reported, others caused damage to homes, downed power lines and uprooted trees.