Updated at 11:39 a.m. Wednesday
Several early commuters drove by the RIPTA bus, which was seen stopped at 6:15 a.m. on West Main Road near the overlook at Lehigh Terrace.
"On Feb. 27, at approximately 6:15 a.m. Portsmouth police were called to the area of West Main Road near Willow Lane in regards to a reported stabbing that occurred on a RIPTA bus," according to a release issued by Portsmouth police.
"When police arrived on scene, they learned that a 46-year-old female resident of Portsmouth had been stabbed by a male passenger shortly after she boarded the bus. Immediately after the stabbing, two other male passengers brought the suspect to the ground and detained him until police arrived."
A State Police trooper was seen running onto the passenger bus at one point. A Portsmouth fire engine and ambulance were also on scene.
"The victim was transported to the Rhode Island Hospital where she was pronounced dead shortly after arrival," according to the release. "The suspect was taken into custody and is to be arraigned on murder charges later today.
"It is important to note that this does not appear to be random act of violence, but rather a domestic related incident."
The suspect has been identified as 46-year-old Christopher R. James with a last known address of 207 Rhodes St., Providence.
The identity of the victim is being withheld by investigators until family members can be notified.
Updated at 1:11 p.m.
James has an extensive criminal history dating back to 1985, according to court records, including a 2011 charge of assault on a person over 60 in which he was remanded to the Adult Correctional Institutions (ACI).
It is unknown how many people were on board the bus at the time of the stabbing. The incident occurred on bus #60, according to WPRI.
There are several RIPTA bus stops in the area, including one in front of the Connor's Funeral Home and several along Bristol Ferry Road.
Check back with Portsmouth Patch later today for more details on this developing story.