(Adds details about Freitekh, instructor, investigation, bylines)
By Mark Hosenball and Joseph Ax
WASHINGTON/NEW YORK, Oct 12 (Reuters) - The U.S. National Transportation Safety Board said on Wednesday it believes a small plane that crashed in East Hartford, Connecticut on Tuesday was intentional, and that the FBI would lead the investigation.
The twin-engine plane slammed into a utility pole and burst into flames on Tuesday near the headquarters of aerospace manufacturer Pratt & Whitney, killing flight student Feras Freitekh and leaving the instructor with serious burns.
In a statement, the NTSB said its initial investigation indicated that the crash was "the result of an intentional act."
East Hartford Police Lieutenant Joshua Litwin said at a news conference on Wednesday that he did not know who was flying the plane at the time of the crash. The aircraft had two sets of controls, allowing either person to pilot the plane, Litwin said.
The New York Times reported that law enforcement sources said the instructor has told investigators the plane was deliberately crashed. The Hartford Courant, citing a high-ranking law enforcement official, reported that the two men argued before the crash.
Federal Aviation Administration records showed Freitekh lived in Orland Hills, Illinois, a suburb of Chicago, and became certified last year as a private pilot for single-engine planes.
A U.S. national security official, who confirmed the identity of Freitekh and requested anonymity to discuss the ongoing investigation, said law enforcement would look into whether Freitekh had ties to terrorism. The official said, however, that Freitekh was not known to U.S. intelligence agencies.
Transportation Secretary Anthony Foxx declined to say if the crash was an act of terrorism. The FBI "is going to dig into the facts," he told reporters on Wednesday.
Police searched an apartment in Hartford where Freitekh was staying and had also interviewed other flight students, the Courant newspaper reported, citing unnamed sources.
CBS News reported that Freitekh, a Jordanian national, first entered the United States in 2012 on a temporary student visa in order to attend flight school. The network said Freitekh also went to a language school in Toledo, Ohio, at one point.
People who said they were relatives of the man mourned him on social media on Wednesday.
"Pray for him for mercy and forgiveness," one person wrote on Facebook in Arabic, saying he was a cousin and that Freitekh, 28, died "after a terrible accident."
Freitekh and a flight instructor were the only people aboard the plane when it crashed at about 3:30 p.m. EDT (1930 GMT) on Tuesday during flight training that originated at the Hartford-Brainard Airport, local police said.
The instructor is being treated at the Bridgeport Hospital's burn center, according to East Hartford Mayor Marcia Leclerc.
The Courant identified the instructor as Arian Prevalla. A LinkedIn profile for Prevalla lists him as the president of the American Flight Academy, a flight school based in Hartford, Connecticut.
Calls to the school went unanswered on Wednesday. Prevalla is originally from Albania and founded the academy in 2006, according to the school's website. The academy's two locations have a total of 21 Piper aircraft. (Additional reporting by Laila Kearney, David Ingram and Gina Cherelus in New York and David Shepardson and Yara Bayoumy in Washington; Editing by Paul Simao and Diane Craft)