Two doctoral students at the University of South Florida are missing, the school's police department said in a statement Tuesday.

Zamil Limon and Nahida S. Bristy, both 27, were last seen on Thursday, the USFPD said.

Limon, a doctoral student who is pursuing a degree in geography, environmental science & policy, was last seen on Thursday at 9 a.m. in his Tampa residence, police said. There has been no contact with him since, and the Hillsborough County Sheriff's Office processed a missing persons report for him.

Bristy was also last seen on Thursday, but at 10 a.m. in the Natural and Environmental Sciences (NES) Building on the USF Tampa campus, according to police. She is studying chemical engineering. The USFPD processed her missing persons report.

Limon's residence is less than a 10 minute drive from the NES Building where Bristy was last seen.

On April 17 just before 5 p.m., a family friend reported that they were unable to contact both Limon and Bristy. That call triggered both missing persons reports and prompted police to enter both Limon and Bristy into missing persons databases.

Officials have said the two are friends and may be together.

Police are asking that anyone who has seen Limon or Bristy, or has information regarding their whereabouts, should contact USFPD at (813) 974-2628.

Police said they will release more information about the case as it becomes available.