Video footage shows a heavy police presence in the area.
Unconfirmed reports claim the man shot a woman while they were driving in a car and then jumped out.
Fire officials said she was taken to South Shore Hospital.
The extent of her injuries is unclear.
It is believed the shooter ran into a heavily-wooded area along Route 3A.
A perimeter has been set up while the authorities search for the man with a state police helicopters and K9 teams.
Volleyball team students are currently on lockdown at Marshfield High School.
It is not yet known if the shooter has been caught by law enforcement officers.
However, Thom Holdgate, the Director of Athletics at Marshfield High School Thom Holdgate communicated on Twitter the volleyball team has been released.
He wrote: I am pleased to report that our volleyball team has been released from lockdown and are heading back to Duxbury.
“Thank you to all members of Marshfield Public Schools and law enforcement members for your help tonight.”