WASHINGTON -- Authorities across the US Midwest braced for the possibility of new deadly tornadoes Monday, after at least eight people were killed when twisters swept through the region over the weekend.

CNN reported that seven people were found dead in the north-central Iowa towns of Parkersburg and New Hartford when a tornado passed at about 6:00 p.m. (2200 GMT) Sunday.

Marble-sized hail also fell over the town of Waterloo, Iowa where authorities reported significant damage to homes, trees and power lines, the report said.

Iowa Governor Chet Culver declared a state of disaster in three counties. Meanwhile, in Minnesota, a separate twister killed a two-year-old child and seriously injured nine other people in the Minneapolis-Saint Paul area, CNN said.

Weather watchers said that all told, there were some 160 reports of tornadoes spanning from Texas to Minnesota, and said new twisters were likely, possibly accompanied by hail, damaging wind and downpours.

Conditions in Texas, Oklahoma and Kansas were particularly propitious for new tornadoes, meteorologists said.

Governor Culver told Fox television that the disaster declaration "allows the local emergency assistance companies to get there faster.

"I am traveling through Parkersburg, (and) this devastation is amazing in its horribleness," said Culver, who said the southern half of the city was flattened.

"You have 200 homes, many of them completely gone. We are mobilizing some guardsmen to come in and try to help," said Culver.

The Iowa governor added that residents and businesses both were in dire need.

"We need assistance in helping them get through the debris. People who want to get back to whatever is left of their homes and salvage and recover everything and everything that they can. That will take time," he told CNN.

"In addition, we are going to need some shelters," Culver said.

"The Red Cross has been extremely helpful because these folks have, in many cases, nothing."

On May 10 tornadoes raked across parts of Missouri, Oklahoma and Georgia, killing 22 people, while in February a string of storms brought rare winter tornadoes to the Southern states of Tennessee, Arkansas, Kentucky and Alabama, killing 55 and injuring hundreds.