US President Barack Obama has condemned the "brutal and outrageous" murders of three Muslim students in North Carolina.
"No one in the United States of America should ever be targeted because of who they are, what they look like, or how they worship," he said in a statement, offering his condolences.
He added: "As we saw with the overwhelming presence at the funeral of these young Americans, we are all one American family."
Shaddy Barakat, 23, his wife, Yusor Mohammad Abu-Salha, 21, and her sister Razan Mohammad Abu-Salha, 19, were killed on Tuesday in the couple's Chapel Hill apartment.
Police have said they suspect the catalyst for the alleged murders by neighbour Craig Stephen Hicks, 46, was a parking dispute, but family members claim it was a hate crime.
The FBI has opened an investigation into the killings to run parallel to that by the local police force.
North Carolina investigators said on Friday that Hicks had at least 12 guns and a large cache of ammunition.
Muslim groups planned to hold Friday prayers in front of the White House as part of their call for a federal hate-crime inquiry.
Mr Obama's remarks on Friday follow criticism from Turkey's President Recep Tayyip Erdogan, a devout Muslim, of his US counterpart's "telling" failure to speak out about the killings.
On Thursday, more than 5,000 people attended the funerals of the students in a ceremony that spilled over from a mosque to an athletic field at North Carolina State University in Raleigh.
The fathers of the three young Muslims, standing before their coffins, said the killings were motivated by religious hatred.
"This has hate crime written all over it," said Dr Mohammad Yousif Abu-Salha, who lost his daughters.
"If they don't listen carefully, I will yell."
The murders saw the hashtag #MuslimLivesMatter trending on social media.
But US Attorney Ripley Rand, the district's top federal prosecutor, has said there was no immediate evidence Muslims were being targeted.
Hicks, 46, is a gun rights advocate with a concealed weapons permit who often complained about organised religion on Facebook.
He turned himself in and is in custody on first-degree murder charges.
The accused, a paralegal student at a local community college, had confronted other residents about parking and noise.
Neighbour Samantha Maness, 25, said Hicks was known in the apartment complex as someone with a short temper.
She described him as displaying "equal opportunity anger towards the residents here".
Hicks' ex-wife told the Associated Press he was obsessed with Falling Down, the 1993 movie about a jobless divorcee who goes berserk.
She said he showed "no compassion at all".