Democratic presidential candidates have accused Donald Trump of encouraging “white nationalism” after two mass shootings left 29 people dead in the US.
Mr Trump said “hate has no place in our country” after the attacks in Texas and Ohio happened within a few hours of each other.
Suspect Patrick Crusius, 21, was arrested after 20 people were killed at a Walmart store in the Texan city of El Paso, which has a large Hispanic population.
Authorities said the gun rampage appeared to be a racially motivated hate crime and federal prosecutors were treating it as a case of domestic terrorism.
Crusius could face the death penalty if convicted over the massacre in El Paso, where police first received reports of gunfire on Saturday at 10.39am local time (4.39pm BST).
Several hours later, a gunman opened fire in Dayton, Ohio, at 1am local time (6am BST) on Sunday.
He has been named by police as 24-year-old Connor Betts who killed nine people, included his own sister, and wounded at least 26 others in an attack lasting around 30 seconds before he was shot dead by officers.
Democratic presidential candidates have criticised the US leader after the mass shootings, saying his language against minorities promotes racial division and violence.
Beto O’Rourke, who was born in El Paso, told CNN: “Let’s be very clear about what is causing this and who the president is.
“He is an open avowed racist and is encouraging more racism in this country.”
Another Democratic candidate, Pete Buttigieg, said Republican Mr Trump was “condoning and encouraging white nationalism”.
New Jersey Senator Cory Booker said: “There is complicity in the president’s hatred that undermines the goodness and the decency of Americans regardless of what party.”
Mexico President Andres Manuel Lopez Obrador said six Mexicans were killed in the El Paso shooting.
He said that the events in Texas reaffirmed his conviction that “social problems shouldn’t be confronted with the use of force and by inciting hate”.
In the past, Mr Trump has called some Mexican immigrants “rapists” and “criminals”.
Before boarding Air Force One for a flight from New Jersey to Washington, he told reporters: “Hate has no place in our country, and we’re going to take care of it.”
The president has also connected the shootings to mental illness but made no direct mention of gun laws.
Amid calls from anti-gun campaigners for tighten controls, America’s National Rifle Association (NRA) said it was “committed to the safe and lawful use of firearms by those exercising their Second Amendment freedoms”.
“We will not participate in the politicising of these tragedies but, as always, we will work in good faith to pursue real solutions that protect us all from people who commit these horrific acts”.
A local prosecutor has announced he will bring capital murder charges against Crusius and said he had “lost the right to be among us” after the Texas shooting.
Investigators are focusing on whether the El Paso attack was a hate crime after the emergence of a racist, anti-immigrant screed that was posted online shortly before the attack.
Using a rifle, the gunman opened fire in an area packed with as many as 3,000 people during the busy back-to-school shopping season.
More than two dozen people were injured, with some in critical condition, police said.
Betts from Bellbrook, southeast of Dayton, was armed with a .223-caliber rifle with magazines capable of holding at least 100 rounds of ammunition.
He was killed at an entrance to a bar where people were taking cover, police chief Richard Biehl said.
Mr Biehl added that if Betts had managed to get inside, the result would have been “catastrophic”.
Police have not identified a motive in what was the second US mass shooting in less than a day.
Betts shot his 22-year-old sister, Megan, during the attack, who has been confirmed as the youngest dead.
Police said the gunman was white and six of the nine people killed were black.
Officers said they would investigate the possibility of a hate crime, but said the quickness of the rampage made any discrimination in the shooting seem unlikely.
The other dead were identified as Monica Brickhouse, 39; Nicholas Cumer, 25; Derrick Fudge, 57; Thomas McNichols, 25; Lois Oglesby, 27; Saeed Saleh, 38; Logan Turner, 30; and Beatrice N Warren-Curtis, 36.
Bett’s former classmate, Brad Howard, said he had known him for two decades. He said: “The Connor Betts that I knew was a nice kid.”
Betts’ neighbour Stephen Cournoyer added that he often saw Betts mowing the lawn or walking the dog.
Mr Cournoyer said: “He seemed like a good kid. He wasn’t a speed demon, didn’t do anything crazy. But that’s not to say, I mean, obviously he had an issue.”
Pictures of the scene captured by witnesses outside Ned Peppers Bar in Dayton showed a police cordon surrounding the area.
Nikita Papillon, 23, was across the street at Newcom’s Tavern when the shooting begun. She said she saw a girl she had talked to earlier lying outside Ned Peppers Bar.
“She had told me she liked my outfit and thought I was cute, and I told her I liked her outfit and I thought she was cute”, Ms Papillon said.
El Paso has around 680,000 residents and sits across the border from Ciudad Juarez in Chihuahua, Mexico.
Source: SKY NEWS