US prosecutors will seek the death penalty for a 21-year-old man, accused of killing 20 people in a mass shooting.

The attack at a Walmart in El Paso, Texas is being treated as a case of domestic terrorism.

The white shooter is believed to have posted an online document 20 minutes before the attack, calling it a response to “the Hispanic invasion of Texas”.

In it, he expresses support for Australian terrorist Brenton Tarrant, responsible for the Christchurch massacre.

The young man, being named by US media as Patrick Crusius, surrendered himself to police out the front of the store and has been “forthcoming with information”.

“He basically didn’t hold anything back,” says El Paso Police Chief Greg Allen who choked back tears.

As the bodies of the 20 victims started being removed from the Walmart, the District Attorney confirmed prosecutors will seek the death penalty.

Just 13 hours after the eighth-worst mass shooting in modern American history, a gunman opened fire at a bar in Dayton, Ohio.

Nine people were killed, including the gunman’s sister, and 27 injured in the space of a minute.

Police responded almost immediately, shooting the gunman dead.

24-year-old white man Connor Betts has been named as the attacker, with witnesses saying he had an assault rifle and body armour.

His motive is unclear at this stage.

The Ohio gun massacre is the 250th in the US this year, the second in 24 hours and the third in a week.

Today, I authorized the lowering of the flags to half-staff at all Federal Government buildings in honor of the victims of the tragedies in El Paso, Texas, and Dayton, Ohio….

— Donald J. Trump (@realDonaldTrump) August 4, 2019