The FBI said Tuesday that it is joining the search for the University of Virginia student who vanished early Sunday morning while walking home from a party.

Hannah Elizabeth Graham, 18, a second-year student, was reportedly last seen inside an off-campus apartment complex in Charlottesville, just before midnight. About an hour after she left the party early Sunday morning, Graham sent a text message to friends saying that she'd gotten lost walking home, WTKR.com reported. She was not heard from again.

Authorities labeled the hunt for the student a "search and rescue" effort.

"Last night we expanded our search about 25 to 30 blocks Right now we are focusing on another five to six block area which is outside of the zone we looked at last night," Capt. Guy Williams, of the Albemarle County Sheriff's Office, told WDBJ7.com.

Graham's family said in a statement Tuesday they are  "heartbroken" since her disappearance.

Police released pictures of Graham in her apartment building at around 9:30 p.m. on the night she vanished. She was described by police as 5 feet, 11 inches tall with a trim build. She was last seen wearing a black crop top.