Alex C. LeBaron, Misch Whitaker, Mike Morrell and Patrick Parhiala perform at a recent ImprovBoston “Cagematch” show. (Photo: Photo Credit: Ryan Kelly Coil)

Note: The cities-wide lockdown brought on by the hunt for the Boston Marathon bombers Thursday night and Friday forced the cancellation of these events.

ImprovBoston is offering free admission to its six Friday shows to provide some healing laughs and collect donations for victims of the violence Monday at the Boston Marathon.

“Laughter is the best medicine we have, and we want to make sure people have access and the opportunity to laugh, especially after the week we’ve had,” said Zach Ward, managing director of the Central Square theater.

Two bombs set off Monday at the finish line of the marathon killed three people, including an 8-year-old boy, and seriously hurt 176. The area has since been rattled by repeated alarms and bomb threats, including on Wednesday at Boston’s John Joseph Moakley United States Courthouse, when a suspect in the bombings was said – falsely – to be in custody.

While admission to all Friday shows at ImprovBoston is free, the theater will be collecting donations for One Fund Boston, formed by Gov. Deval Patrick and Boston Mayor Tom Menino to support the victims of Monday’s bombings.

“We are proud to offer ‘Improv for Boston’ and support the city and the people of Boston,” Ward said.

The shows Friday are:

Studio 40, 7:30 p.m. Independent Sketch and improv comedy performed by theater teams.

The ImprovBoston Mainstage, 8 p.m. An evolving show in which top theater-trained improvisers create “a show that redefines itself with every performance,” blending storytelling, music and audience participation with “No rules. No boundaries. Just spectacular comedy and incredible improvisation.”

Cagematch, 9 p.m. Teams get 22 minutes performing head-to-head long-form improv comedy, with the audience deciding the winner.

The ImprovBoston National Tour Co., 10 p.m. A showcase performance from the theatre’s nationally renowned touring company featuring the most popular and booked company formats.

Vinyahahasa, 10:30 p.m. Combining yoga and comedy, the show take an eccentric yoga teacher and four performers embedded in the audience and explores the meditative arts with a story “filled with love triangles, inner monologues, vengeance, insecurity, pride and plenty of Downward Dog.”

Nightcap, 11:30 p.m. This standup and improv half-hour show is free every week.