An Arlington man was severely burned early yesterday morning by a fire that consumed his car on a Rte. 7 off-ramp. Virginia state police and Fairfax County fire investigators are trying to determine whether the incident was a murder attempt, said spokesmen.

The victim was identified by police as Chantha Kheng, 25, of 1001 S. Frederick St.

Kheng "made a statement to officers on the scene that someone set him on fire," said 1st Sgt. Dennis W. Robertson, who heads the state police office in Arlington.

Kheng suffered second- and third-degree burns over 80 percent of his body and was taken by helicopter to the burn center at the Washington Hospital Center. He is in critical condition, said Clare Fiore, a hospital spokeswoman.

Kheng told family members that he had been accosted by four men as he was leaving his job at the Marriott Hotel at Tysons Corner yesterday, said Curtis M. Moore, a special agent with the State Police Bureau of Criminal Investigation.

"He was driving. They apparently struck him. After that it gets sketchy," said Moore, who confirmed the details with Kheng.

The incident occurred about 3:45 a.m. on the Rte. 7 ramp to eastbound I-66 in Fairfax County about a half-mile from Falls Church, said authorities.

When units from the Fairfax County Fire Department arrived they found Kheng about 500 feet from his car. Both Kheng and the car were on fire, said Sgt. Tom Wolfe, a fire department spokesman.

Investigators have determined that the blaze was "set" and not a spontaneous fire caused by a malfunction of the car, said Wolfe. "It could have been accidentally set or deliberately set, we really don't know," said Wolfe. The car, a late-model Toyota, was destroyed.

There were no witnesses to the incident, said Lt. D.P. Garrett, a state police spokesman.