Freak US-Mexico tornado rips baby girl from mother's arms

At least 13 have been killed in the whirlwind which destroyed homes and flung cars like matchsticks

Residents of Ciudad Acuna stand by their homes after the tornado swept through the boder city (Reuters)

A tornado raging through a city on the US-Mexico border has killed 13 people and ripped an infant from its mother's arms.

The tornado swept through the northern Mexican city of Ciudad Acuna, home to 125,000, flipping over cars and tearing down homes.

The 13 dead included three babies, while hundreds of people were injured.

In Texas, 12 people were reported missing in flash flooding after waves swept through a small town popular with tourists.

The baby was also missing after the twister tore the child's carrier from her mother's hands and sent it flying, said Victor Zamora, interior secretary of the state of Coahuila.

In Ciudad Acuna, at least 300 people are being treated at local hospitals, and up to 200 homes had been completely destroyed, officials said.

"There's nothing standing, not walls, not roofs," said Edgar Gonzalez, a spokesman for the city government.

Rescue workers dug through the rubble of damaged homes in a race to find victims. The twister hit a seven-block area, which Mr Zamora described as "devastated".

Photos from the scene showed cars with their hoods torn off, resting upended against single-story houses.

Family members and neighbours gathered around a pickup truck where the bodies of a woman and two children were laid out in the truck’s bed, covered with sheets.

Cars were bent and crushed in the US-Mexico whirlwind (Getty)

The twister struck not long after daybreak, at around 6:40am - the time buses were preparing to take children to school.

President Enrique Peña Nieto said he planned to travel to Acuna.