At least seven people are reported to have been killed by a tornado that hit the northern Mexico border city of Ciudad Acuna, BBC News reports.

Scores of homes have been destroyed in the city, in Coahuila state, which is just across the border from Del Rio, Texas.

Images from the scene showed cars upended and leaning against buildings.

Local media said the death toll could rise as more destroyed homes were searched.

"There are cars on top of houses, there are dead people lying in the street, it is total chaos," said local resident Maria del Rosario Ramirez, quoted by Mexican newspaper La Jornada.

Rosario Cano, a spokeswoman for Coahuila's interior department, said the tornado had struck at about 06:40 (11:40 GMT). She said that senior state officials were reviewing the damage and coordinating a response to the disaster.