Law enforcement officials have gathered near the commuter rail tracks in Medford.
Police, fire and ambulance crews could be seen investigating an area along the tracks Wednesday morning.
No additional details were immediately available.
Update: Haverhill Train 206 (6:40 am from Haverhill) is operating 25-35 minutes late between West Medford & North Station due to police activity.
— MBTA Commuter Rail (@MBTA_CR) April 18, 2018
This is a developing news story, 7News will post more information as it becomes available.