An Arab gunman who went on a shooting rampage at Los Angeles airport had set out to kill, officials said Friday, as US and Israeli officials tussled over whether the attack was an act of terror.

The comments as investigators picked through the home of Egyptian immigrant Hesham Mohamed Hadayet for clues as to why he opened fire at an El Al Israel Airlines ticketing counter Thursday, killing two people and injuring four before he was shot dead by Israeli security agents.

The Federal Bureau of Investigation (FBI) said 41-year-old limousine driver Hadayet had intended to murder people when he turned up at Los Angeles International airport on his birthday Thursday armed with two guns and a knife.

But Special Agent Rich Garcia said his motives remained murky, despite the insistence of Israeli officials and US Jewish groups that the shooting was an anti-Israeli terror attack.

"It appears that he went there for the intention of killing people," Garcia told reporters. "Why he did that, is still undetermined. That's what we are trying to find out."

The agent declined to classify the shooting spree that took place as passengers queued for an El Al flight to Tel Aviv as a terrorist attack, saying it was too early to draw conclusions.

"We are not ruling out hate crimes, we are not ruling our terrorism completely and we are not ruling out that it may have been a random act of violence.