Boston police increased their presence Thursday morning in the Back Bay after they were alerted to a potential threat.

Officers were alerted shortly before 7:30 a.m. in the area of 200 Clarendon St., police said.

After investigating the report, officers found the incident to be an uncorroborated threat of unknown reliability, police said.

The police department nevertheless increased its uniformed presence in the area as a precaution.

Local, state and federal authorities are coordinating to identify the source of the threat.