In an investigation into the killing of three Muslims, the FBI is looking for signs of a hate crime.

The Federal Bureau of Investigation is investigating whether any federal laws were violated in the case of the murder of three Muslims who were shot this week near the campus of the University of North Carolina at Chapel Hill. Friends and relatives of the victims call this incident a hate crime.

“The FBI continues to assist Chapel Hill Police with information related to the triple homicide investigation,” the North Carolina FBI field office said in a brief statement emailed to VOA. “The FBI is also conducting a parallel preliminary investigation to determine whether there are violations of federal laws in this case.”

Two sisters and the husband of one of them were killed on Tuesday in an apartment building near the campus of the University of North Carolina in the city of Chapel Hill.

Their neighbor, 46-year-old Craig Stephen Hicks, was charged with first-degree murder. Police believe that the reason for the attack on the newlyweds Dea Shaddi Barakat and Yusor Abu-Shalha, as well as the woman’s 19-year-old sister Razan Abu-Shalha was a long-standing conflict between neighbors because of the parking space.

However, the father of the murdered sisters, Mohammed Abu-Shalha, said on Wednesday that he considered murder a hate crime. According to him, Hicks has several times threatened his daughter and her husband with a gun at the waist.

The law defines a hate crime as a criminal offense, at least in part motivated by prejudice about race, religion, ethnic or national identity, gender, sexual orientation or physical disability.

According to the FBI, in 2013, US law enforcement agencies reported more than 6900 hate crimes. Religion is one of the most common motives, with 165 crimes motivated by prejudices against Muslims.

On Wednesday evening, a funeral prayer by candlelight took place on the campus of the University of North Carolina in memory of the victims. This case also caused resonance at the international level - for example, Turkish President Recep Tayyip Erdogan called on the US authorities to condemn the killings.

On Thursday, talking to reporters during a visit to Mexico, Erdogan criticized President Obama, Vice President Joe Biden, and Secretary of State Kerry because they did not comment on the attack.

“If you remain silent after such an incident, the world will also answer you with silence,” said the Turkish leader, who himself professes Islam and has repeatedly spoken out about Islamophobia in the West.

Twitter launched a campaign with the hashtag #MuslimLivesMatter (Muslim lives are important), which also attracted attention around the world. Many outraged users believe that the case did not receive enough publicity, because the victims were Muslims. One user tweeted: “Muslims are interested in the media only when they hold a gun, and are not at gunpoint.”

A number of organizations, including the Council on American-Islamic Relations, also called on police to investigate the triple murder as a hate crime, writes VOA News Service.