HOUSTON -

A series of crimes over the last 24 hours in the vicinity of Rice University and the Texas Medical Center have officers at several police agencies on heightened alert.

The most recent incidents on Thursday morning caused police for a short time to lock down HCC's Coleman College for Health Sciences. The area is densely populated by higher learning institutions.

An alert by UT Health Center Police read: "A armed robbery just occurred at 6700 Travis Street. Suspect was armed with a black handgun and is described as a black male, approximately 15 yoa, thin build, wearing a lavender striped polo shirt, jeans and a black back pack with a UT Longhorns logo. Avoid the area."

Houston police representatives reported the suspect was involved in two separate incidents about 9:30 a.m.

On the 2100 block of West Holcombe, the robber stole a cell phone from a woman.

On the 6700 block of Travis, a UT Health Center employee reported a man with a gun attempted to rob her. That second victim described the suspect as a black juvenile male.

UT police said the lockdown on the HCC-Coleman campus started around 10:30 a.m. It was lifted about an hour later.

No further information was available.

On Wednesday night, outside Rice University's Bioscience Research Collaborative, a Rice University staff member was approached by 6-10 "well dressed" men. Rice University Police called the crime "an attempted strong arm robbery". The staff member was not injured. It is unclear if the incident is connected to the others.

No suspects are in custody.

Police are reviewing surveillance video in the area hoping to gather more information about the suspect and these crimes.

If you have any information about the crimes or similar incidents, contact Rice University Police at 713-348-6000 or the Houston Police Department at 713-884-3131.