WASHINGTON

Convicted sex offender and former USA Gymnastics doctor Larry Nassar was stabbed multiple times while in a federal prison in Florida over the weekend.

The prison where Nassar, 59, is being held -- United States Penitentiary, Coleman -- did not identify him by name, but confirmed that an inmate was assaulted on Sunday afternoon at roughly 2:35 pm local time (1835 GMT). Multiple reports identified the inmate as Nassar.

The prison said staff members who responded to the incident "immediately" rendered "life-saving measures," and requested emergency services to provide further aid. The inmate was then transferred to a local hospital for additional medical care, the prison said in a statement.

An internal probe has been launched to investigate the assault, the agency said.

Nassar was stabbed twice in the neck, twice in the back and six times in the chest, NBC News reported, citing information provided by Joe Rojas, president of Local 506, a union that represents employees at the prison. Rojas told NBC that Nassar is in stable condition.

Nassar has been serving a prison sentence of up to 175 years since 2018. More than 150 gymnasts and women accused him of molesting them over a span of two decades.

In sentencing Nassar to between 40 and 175 years behind bars, Judge Rosemarie Aquilina told Nassar she had "just signed your death warrant."

"You still think that somehow you are right, that you are a doctor, that you are entitled, that you don't have to listen. And that you did treatment. I wouldn't send my dogs to you, sir," said Aquilina.

Nassar had earlier been sentenced to 60 years in prison after pleading guilty in a separate federal child pornography case.