Washington - At least 22 people were killed Saturday and many injured as tornadoes ploughed across the mid-west and south-east of the United States, reports said Sunday. The numbers injured and the extent of the damage to property and infrastructure was still unclear, US broadcaster ABC reported.
The electricity supply was severed in many places as utility poles were uprooted, leaving thousands of people without power.
Speaking Sunday in Texas, US President George W Bush spoke of a "sad day" for many in the tornado-hit areas as the country marked Mother's Day.
"I understand that for some, however, Mother's Day is a sad day for those who lost their lives in Oklahoma and Missouri and Georgia because of the tornadoes, are wondering whether or not tomorrow will be a bright and hopeful day," he said. "We send our prayers to those who lost their lives, the families of those who lost their lives."
Federal authorities and state governments would do everything to help, he said.
Numerous people were reported missing Sunday, while rescue and fire services were searching many ruined buildings in the most remote areas for people who might have become trapped. Many people were still missing, ABC television reported.
The south-east of the US was bracing for more storms Sunday. The states of Oklahoma, Arkansas and Missouri have been worst-hit by the storms that have been raging since Thursday.
In Oklahoma alone, five tornadoes have been registered. At least 14 people were killed in Missouri, the majority near Seneca close to the Oklahoma border, where in the small town of Picher seven people died, including a young child.
Another person also died Sunday in the state of Georgia, CNN reported.
"Our thoughts and prayers are with the people in Picher," said a statement by the governor of Oklahoma, Brad Henry, who was to visit the worst-hit places Sunday.
At least 150 people have been injured in Oklahoma alone, CNN said.
Several trees had been uprooted and cars tossed through the air while in Arkansas many people were trapped in collapsed buildings, ABC reported.
Rescue services were trying to help them.
