WASHINGTON — Part of Johns Hopkins Hospital’s complex in Baltimore was evacuated Thursday afternoon because of possible tuberculosis exposure.

A small sample of frozen tuberculosis was accidentally released when it was being transported on a bridge between two research buildings around 2 p.m. The buildings, located in the 1600 block of Orleans Street in Baltimore, are non-patients areas and do no connect to the hospital.

As a precaution, the research buildings were evacuated. Around 5 p.m., Johns Hopkins announced the buildings had been cleared and the evacuation was lifted.

Employees who in the area during the incident were isolated and evaluated and later cleared. The hospital confirmed there was “no risk to anyone on campus,” said Kim Hoppe, a hospitals spokeswoman.