(Adds statement by FBI on separate inquiry in paragraph 4, background on Erdogan in paragraph 7)
By Colleen Jenkins
WINSTON-SALEM, N.C., Feb 12 (Reuters) - Thousands of mourners attended the funeral prayers on Thursday for three young Muslims killed in North Carolina, and the father of two of the victims urged U.S. authorities to probe whether religious hatred was a motive for the murders.
Newlywed Deah Barakat, 23, a University of North Carolina dental student, his wife Yusor Abu-Salha, 21, and her sister, Razan Abu-Salha, 19, a student at North Carolina State University, were gunned down on Tuesday in a condominium about two miles (three km) from the UNC campus in Chapel Hill.
Police charged the couple's neighbor, Craig Stephen Hicks, 46, with murder. Investigators say initial findings indicate a dispute over parking prompted the shooting, but they are looking into whether Hicks was motivated by hatred toward the victims because they were Muslim.
The FBI said it was opening its own preliminary inquiry, separate from local police investigations. A statement by FBI spokeswoman Shelley Lynch did not specify if the inquiry would include whether the shooting was a hate crime.
The case has garnered international attention and Turkish President Tayyip Erdogan criticized President Barack Obama, Vice President Joe Biden and Secretary of State John Kerry on Thursday for not speaking about the incident.
"If you stay silent when faced with an incident like this, and don't make a statement, the world will stay silent towards you," Erdogan said during a visit to Mexico.
The Turkish president, a devout Muslim who has been outspoken against what he sees as rising Islamophobia in the West, has strained relations with Obama on issues such as the war in Syria. The White House said on Wednesday it would wait for the results of the police investigation before commenting on the killings in North Carolina.
The murders have prompted vigils and the hashtag #MuslimLivesMatter on social media, and raised concerns among some Muslim advocates in the United States who say they have seen an increase in threats against their communities in recent weeks.
Speaking to mourners in a field near a mosque in Raleigh, the women's father, Mohammad Abu-Salha, called on Obama to insist that the FBI investigate the case as a possible hate crime.
"This has hate crime written all over it," he said. "If they don't listen carefully, I will yell."
He said the victims' families did not want revenge or care about Hicks' punishment, but rather sought to ensure that other young people in the United States would not suffer similar violence.
The FBI designates as hate crimes those that are motivated or partly motivated by bias against race, religion, ethnicity, disability, gender or sexual orientation. Such crimes generally carry greater penalties.
According to FBI statistics, U.S. law enforcement agencies reported roughly 6,900 offenses motivated by bias in 2013. Of those, 165 offenses were crimes resulting from bias against Muslims, the data shows. None were murders.
ANGRY OVER PARKING, NOISE
Hicks' wife and some neighbors have said he appeared angry about parking at the condominium where he lived, not motivated by hatred of Muslims.
A paralegal student at Durham Technical Community College since 2012, Hicks portrayed himself on Facebook as an atheist and filled his social media page with anti-religion posts.
Neighbor Samantha Maness, 25, said he was known in the condo community as someone quick to anger over parking troubles and noise. He had confronted her and friends in the past when he thought they were being too loud, she said.
She said she never saw him show any animosity along religious or racial lines, describing his behavior as "equal opportunity anger towards the residents here."
The suspect's wife of seven years, Karen Hicks, told news station WRAL she believed her husband grew upset when he returned home from school on Tuesday and found someone in his designated parking space.
She suspects something in him "snapped the wrong way," she said in a videotaped interview.
Police in Chapel Hill had not released any new details about their investigation on Thursday. (Reporting by Colleen Jenkins; Additional reporting by Alberto Fajardo in Mexico City; Editing by Frances Kerry and Cynthia Osterman)