Marblehead parents filed a lawsuit protesting the suspension of extracurriculars during an ongoing teachers strike, as picket lines set up outside schools in three North Shore towns and tensions escalated Tuesday.

Educators in Gloucester, Marblehead, and Beverly are facing hefty fines if they don’t return to the classroom. A judge ordered Gloucester and Beverly teachers unions<a class="excerpt-read-more" href="

While the three strikes are separate, some of the sticking points have been the same — as they have in a recent wave of other teacher strikes across the state.