Officials say at least two volunteer search parties have joined police in investigating the disappearance of a 21-year-old woman who was last seen in South Kingstown late last week.

WPRI-TV reports police say Alicia Storti was last seen just after midnight Friday in the southern Rhode Island town.

Capt. Joel Ewing-Chow reported Monday that both South Kingstown and Narragansett officers have been investigating places that Storti was known to frequent, but no "credible information or evidence" has led police to search any specific locations.

Groups of volunteers assembled Monday in South Kingstown and Exeter to comb the area for clues regarding Storti's whereabouts.

Police say Storti is 5 feet, 2 inches, and weighs about 105 pounds. She has fair skin, shoulder-length brown hair and brown eyes.