U.S. President Barack Obama has called the shooting deaths of three Muslims near a college campus in North Carolina "brutal and outrageous murders."
"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," said the president in a written statement.
Obama also confirmed the U.S. Federal Bureau of Investigation [FBI] has opened in inquiry into the killings to determine whether federal laws were violated.
Watch related video report by VOA's Jerome Socolovsky
Family and friends of the victims are calling the shootings a hate crime. Two sisters and the husband of one of the women were murdered Tuesday at an apartment complex outside the University of North Carolina campus in the town of Chapel Hill.
"The FBI is continuing to provide assistance to the Chapel Hill Police Department to process evidence related to a triple homicide investigation," the FBI's North Carolina field office said in a brief statement emailed to VOA.
"The FBI has also opened a parallel preliminary inquiry to determine whether or not any federal laws were violated related to the case."
U.S. Attorney General Eric Holder said he was shocked and saddened by this week's "heinous murders."
“In addition to the ongoing local investigation, I have made available the full resources of the Department of Justice to help ensure that justice will be served in this case," said Holder. He said securing the civil rights of everyone in America is a top priority for the Justice Department.
A neighbor, 46-year-old Craig Stephen Hicks, has been charged with first-degree murder in connection with the killings. Police believe a long-simmering dispute over a parking space sparked the shootings of newlyweds Deah Shaddy Barakat, his wife Yusor Abu-Salha and her sister, Razan Abu-Salha.
Last summer, Yusor Abu-Salha spoke with StoryCorps about her third-grade teacher.
But the father of the slain women, Mohammad Abu-Salha, said Wednesday he believes the shootings were a hate crime. He said Hicks had confronted his daughter and her husband a few times while carrying a gun on his belt.
The government defines a hate crime as a criminal offense at least partly motivated by bias against race, religion, ethnicity, national origin, gender, sexual orientation or disability.
In 2013, U.S. law enforcement reported more than 6,900 hate crime offenses, according to FBI statistics. Religion was one of the top three bias categories, with 165 offenses stemming from bias against Muslims.
The case is also drawing international condemnation, with Turkish President Recep Tayyip Erdogan calling on top U.S. officials to denounce the killings.
Speaking to reporters Thursday during a visit to Mexico, Erdogan criticized the president, Vice President Joe Biden and Secretary of State John Kerry for their silence over the attack.
"If you, after an incident, an attack like this, remain silent, the world will also stay silent towards you," said the Turkish leader, a devout Muslim who has been outspoken about what he calls rising Islamophobia in the West.
The White House said Wednesday it would wait for the results of the police investigation before commenting on the killings.
Social media reacts
A Twitter campaign using the hashtag "#MuslimLivesMatter" also attracted supporters from across the globe, many angrily claiming the case was being ignored because the victims were Muslim. One poster tweeted "Muslims only newsworthy when behind the gun, not in front."
Groups such as the Council on American-Islamic Relations have also called on police to investigate the shootings as a hate crime.
Chapel Hill police chief Chris Blue issued a statement saying investigators were exploring what could have motivated Mr. Hicks to commit such a senseless and tragic act.
"We understand the concerns about the possibility that this was hate motivated and we will exhaust every lead to determine if that is the case," Blue said.
Ripley Rand, a federal prosecutor whose district includes Chapel Hill, said Wednesday the shootings appeared to be an isolated incident, and not part of a campaign against the Muslim community.
Suspect posted anti-religious statements
Hicks, who was studying to become a paralegal, had posted anti-religious statements on his Facebook page and recently posted a picture of a handgun. But his wife insisted during a news conference Wednesday the murders "had nothing to do with religion or the victims’ faith," adding that her husband was a strong supporter of gay and abortion rights.
Barakat, 23, was a second-year dentistry student at UNC, while Yusor Abu-Salha, 21, was scheduled to join her husband as a dental student in the fall. Razan Abu-Salha, 19, was visiting her sister and brother-in-law from Raleigh, where she was a student at North Carolina State University.
Liban Abdikarim, a Somali-American student who attended UNC with Barakat, told the VOA Somali Service the trio were "leaders" in the Chapel Hill and Raleigh communities. Barakat worked with a charity that provided dental supplies to the poor; he had launched a fundraising campaign for a humanitarian trip to Turkey to provide dental care to refugees from the civil war in Syria.
The families buried their dead Thursday in the nearby North Carolina town of Zebulon.
Some material for this report was contributed by VOA's Jerome Socolovsky and Reuters.