Federal agents are investigating the car explosion that critically injured a prominent Arkansas doctor and cost him one eye, a spokesman with the Bureau of Alcohol Tobacco and Firearms told FOX News.

The explosion occurred Wednesday in the driveway of Dr. Trent P. Pierce, chairman of the Arkansas State Medical Board.

West Memphis Police Chief Bob Paudert said "some type of explosive device" blew up in Pierce's car when he left his West Memphis home to go to work.

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"We don't know if this was a random target or someone specifically targeted him," said Paudert. He said it wasn't known if the doctor was in his car or outside it when the device exploded.

Pierce's white Lexus hybrid sat in the driveway after the explosion, its hood open and bumper partially torn away.

The doctor was taken to Regional Medical Center in Memphis, Tenn., where he was listed in critical condition, hospital spokeswoman Sandy Snell said.

Paudert said Pierce lost one eye in the explosion and remained in surgery late Wednesday afternoon, after suffering severe burns to his face and shrapnel wounds.

"They're contemplating moving him to Ohio to a specialized burn unit," the police chief said.

Paudert said Pierce remains sedated and investigators have yet to speak with him. His injuries are reportedly not life-threatening.

The FBI said a second person was injured outside Pierce's home, but Paudert said only one was hurt.

Board attorney William Trice said he had no information on what caused the explosion.

He said he knew of no disputes the chairman was involved in and said Pierce doesn't even vote on many board matters.

"This is just off the wall," Trice said. "It's just such bizarre circumstances."

Pierce, however, is named as a co-defendant in a case that last month made its way to the Arkansas State Supreme Court, where his motion to dismiss the appeal was granted Jan. 22.

Click here to read the judge's decision to dismiss the appeal. (pdf)

The lawsuit was brought by the estate of a deceased woman, Norma Louise Ramsey, against Pierce, a senior citizens' medical facility company called Golden Living — formerly known as Beverly Enterprises — the Memphis Dermatology Clinic and other defendants.

Ramsey was 92 years old when she died in July 2004, according to her obituary in The Arkansas Democrat-Gazette. There was no cause of death given.

In 2005, the state of Arkansas paid $1.5 million to settle 26 lawsuits brought against Beverly Enterprises. The suits stemmed from allegations of mistreatment and neglect of residents at 12 of its nursing homes.

It wasn't immediately clear whether the lawsuit naming Pierce as a co-defendant with Beverly Enterprises was among the 26 abuse cases. His medical license is listed as active.

A spokesman for Golden Living told FOXNews.com that he was looking into the matter.

In 2006, the Fort Smith, Ark.-based Beverly Enterprises was again sued — this time for $155 million in the neglect and eventual death of 84-year-old Loren Richards by his daughter and estate, according to the Gazette. The case went to trial.

The company has paid millions in wrongful-death lawsuits brought in several states in addition to Arkansas, including Mississippi, Florida and Virginia, the paper reported.

In one such case in Evansville, Ind., the death of an 86-year-old woman who lived at one of the nursing homes was ruled a homicide by neglect.

Pierce had been due in Little Rock later Wednesday for medical board meetings, which will last through the week. The board is responsible for licensing and disciplining doctors in the state.

The board agenda includes at least seven doctors who previously faced discipline.

The ATF would not confirm what type of device was involved in the explosion, but said a "bomb truck" was at the scene.

Two agents from the FBI's national headquarters have joined the ATF and local law enforcement on the scene. Authorities are interviewing witnesses.

Neighbor Julanne Ingram said she heard the blast about 8 a.m.

"It was a huge explosion," she said. "It rattled the windows in this house."

Pierce, a family physician and asthma specialist, was appointed in January 1997 by former Gov. Mike Huckabee. He is in his 50s, is married and has two grown children, his lawyer said.

Click here for more on this story from FOX16.com.

FOXNews.com's Catherine Donaldson-Evans and The Associated Press contributed to this report.