Two mass shootings left at least 29 people dead and dozens injured in the United States in weekend.  

Media reports say a massacre at a Walmart superstore in El Paso, the Texas border city, left at least 20 people dead.

Investigators in El Paso reportedly said that the massacre at the Walmart superstore had been preceded by the suspected gunman publishing an anti-immigration screed via the darker recesses of the internet.

The suspect in the El Paso shooting on Saturday was from the town of Allen, on the outskirts of Dallas, Texas.  He was arrested and is being held in custody.  Local prosecutors charged a 21-year-old white man, Patrick Crusius, with murder and said they would pursue the death penalty and federal authorities are investigating it as a hate crime, according to The Guardian.

Another mass shooting took place in the early hours of Sunday, August 4 just 13 hours later in Dayton, Ohio. CBS News says a gunman in Dayton, Ohio, opened fire in the city’s downtown area around 1am on Sunday, killing nine people. He was armed with a high-powered rifle and a 100-round magazine before police shot him dead within 30 seconds of his beginning a rampage.

Law enforcement named the Dayton shooter as 24-year-old Connor Betts. Betts’s 22-year-old sister Megan was among the victims. The incident was still in the early stages of investigation and it was too early to assign a motive, the Dayton police chief, Richard Biehl, said on Sunday.  

The shootings were carried out just a week after a 19-year-old, also armed with a high-caliber rifle, opened fire at a popular annual food festival in Gilroy, northern California, killing three and wounding others.