WASHINGTON, Aug 5 — Mass shootings in two US states killed at least 29 people over the weekend within hours of each other. Here is what is known about Saturday's shooting in El Paso, Texas, and the early yesterday shooting in Dayton, Ohio:

What happened in each attack?

In El Paso, a major city on the border with Mexico, a lone gunman with an assault rifle opened fire on shoppers at a packed Walmart store, killing 20 people and wounding 26.

In Dayton, a lone shooter wearing body armour and armed with a long gun killed nine people and wounded 27 shortly after midnight in a nightlife district before being shot dead by police, officials said. They said he could have killed "dozens” or "hundreds” if police had not responded quickly.

Who were the shooters?

Police said a man from Allen, Texas, was being held for the El Paso shooting; they said he was cooperating with investigators. US media identified him as Patrick Crusius, a 21-year-old white man from the Dallas area. Prosecutors said they would seek the death penalty.

In Dayton, police identified the shooter as 24-year-old Connor Betts, a white man from nearby Bellbrook, Ohio. His sister was among the victims.

What were their motivations?

The El Paso shooter had reportedly posted what police said was a racist manifesto shortly before the attack. Its author railed against the "Hispanic invasion” of Texas.

The motive of the Dayton attack was unclear, though the shooter's weaponry suggested an intention to kill large numbers of people. It was unclear whether he specifically targeted his sister.

Who were the victims?

Mexican officials said six of the dead in El Paso came from Mexico, and others were among the wounded. Mexicans frequently visit El Paso to shop. News reports said the victims' ages ranged from two to 82 years.

Dayton police said the nine victims ranged in age from 22 to 57; six were African-American. The youngest victim was identified as Megan Betts, the shooter's sister. They denied reports that she had been found dead in a car with her boyfriend. — AFP