Authorities say an elderly woman was repeatedly stabbed in her New Jersey home by a Georgia woman who was staying at the residence.

But it's not yet known what spurred the attack in Cedar Grove.

Police responded to the home around 4 a.m. Monday after the victim's husband reported his 86-year-old wife had been attacked in her bedroom. She had been stabbed 15 times and was taken to a hospital, where she remains in critical condition.

The alleged assailant, Tanya Spears, was found in a first-floor guest bedroom. The 60-year-old Cumming, Georgia, resident is charged with criminal attempt to commit murder, aggravated assault and two weapons charges. Police say no motive for the attack has been discovered. 

It's not known if Spears has retained an attorney.

No other injuries were reported in the attack, which remains under investigation.