UPDATE 2-Alabama tornadoes kill at least 23, including children

Rescuers in Alabama on Monday dug through the remnants of homes and businesses destroyed by a pair of tornadoes that killed at last 23 people, including children, the deadliest such storms to strike the United States in almost six years. The tornadoes ripped through the state's Lee County on Sunday with winds of at least 150 miles per hour (240 kph), at the midpoint of the five-step Enhanced Fujita scale, which meteorologists use to measure tornado strength.

Mobile homes were tossed on their sides and ripped open, their contents strewn on the ground, live television images showed. Pieces of homes hung from trees that were not flattened by the storm. More than 50 people were reported injured and the death toll is expected to rise, authorities said, which could make the storms deadlier than the tornado that tore through Moore, Oklahoma, in 2013, killing 24 people.

"It looks almost as if someone took a giant knife and just scraped the ground. There are slabs where homes formerly stood, debris everywhere, trees are snapped," Lee County Sheriff Jay Jones told a morning news conference. "I've not seen this level of destruction ever in my experience in Lee County." One of the dead was a 6-year-old child, Jones said.

Two of the injured have sustained critical injuries and at least 20 people remain unaccounted for, Lee County Coroner Bill Harris told CNN. On Twitter on Sunday, U.S. President Donald Trump urged affected residents of Alabama and other areas to be "careful and safe."

"To the families and friends of the victims, and to the injured, God bless you all!" he tweeted. Temperatures in the state fell to 36 degrees Fahrenheit (2 Celsius) on Monday, leaving some who lost heat because of the storms to struggle with the cold. (Additional reporting by Gabriella Borter in New York and Rich McKay in Atlanta; Editing by Scott Malone and Jeffrey Benkoe)