An
officer assisting with school dismissal was reportedly on the scene
moments after a fight broke out next to City Hall around 2:45 p.m.,
where the officer found the 16-year-old stabbed in the chest.

The
victim, a Somerville High School student, was transported to
Massachusetts General Hospital with non-life threatening injuries,
according to statement from the Somerville Public Schools.

Niall
Vallega, 19, was arrested on charges of assault and battery with a
dangerous weapon and armed assault with intent to murder. Alieu Joof,
19, was arrested on a charge of being an accessory after the fact. Both
are Somerville residents although neither is a students at the high
school.

Deputy Chief Paul Upton said in a statement that the
victim and alleged assailant knew each other and that the altercation
"was the result of a personal issue."

Vallega and Joof were arraigned Tuesday. A third suspect is still being sought.