A video has emerged of a woman hiding under a table with the sound of gunfire in the background at a Walmart in El Paso, Texas on Saturday.

On Saturday a gunman armed with a rifle killed 20 people at a Walmart in El Paso and wounded more than two dozen before being arrested, authorities said, after the latest US mass shooting sent panicked shoppers fleeing.

Police said the El Paso shooting suspect opened fire with a rifle on shoppers, many of them bargain-hunting for back-to-school supplies, then surrendered to officers who confronted him outside the store.