Local transit officials are reacting to an attack on the London Underground system.
MBTA Superintendent Richard Sullivan said plainclothes officers will be riding public transit.
In a statement, Sullivan said Friday's terror attack in London "serves as a stark reminder transit systems around the world are a target rich environment for those with nefarious intent."
Sullivan said while there are no credible threats against the MBTA at this time, the officers riding the T are specially trained to detect threatening behaviors. They will also closely monitor the public safety camera system.
The MBTA's management is encouraging riders to go about their business but also to remain aware of their surroundings.
MBTA Transit Police are also reminding riders to alert them if they see anything suspicious.
Twenty-two people were injured following an improvised bomb blast and stampede in the London Underground during Friday morning's commute. Police say they are investigating the incident as a terrorist attack.