A cluster of eight coronavirus cases has been traced to a wedding that was held on Martha’s Vineyard over Columbus Day weekend and violated state guidelines regarding travel protocol, according to Island health officials.

In a press release that went out Tuesday, Tisbury health agent Maura Valley said the six boards of health were investigating a cluster outbreak stemming from a wedding which was held on the Island. Eight individuals have tested positive for the virus, six of whom have been or are in isolation on the Island, the release said.

“The source of the outbreak is believed to be event guests who left the Island the morning after the event,” the release said. “Contact tracers have reached out to the individuals connected to this event to advise them of their exposure and their need to quarantine and be tested. We continue to investigate in the hopes of preventing any further spread associated with the event.”

The cluster outbreak is the first such event reported on the Island since the pandemic began. While other seasonal communities in and around the Cape and Islands have reported large gatherings that led to virus outbreaks, including a church gathering on Nantucket earlier in October, the Vineyard has largely avoided community spread, with most reported cases isolated incidents involving family members, according to health officials.

Speaking with the Gazette Tuesday, Ms. Valley said four of the eight individuals who have tested positive were workers involved with the wedding. The other four individuals to test positive were guests. Among the eight positive cases, two have been released from isolation, two have been referred to off-Island health departments, and the other four remain in quarantine.

The first positive test connected to the wedding occurred on Oct. 20, Ms. Valley said. After that, health officials contact-traced the individual to the wedding, and learned that others in attendance had tested positive off-Island. Health officials then contact-traced all other attendees, discovering the rest of the reported positive tests.

The outbreak continues to be investigated, Ms. Valley said.

State travel guidance issued in July requires most out-of-state visitors to quarantine for 14 days upon arrival in Massachusetts or provide proof of a negative Covid-19 test three days prior to travel. Travelers are also required to fill out an out-of-state travel form.

Ms. Valley said those rules were violated by guests at the wedding. The individuals who violated the rules were not fined because the boards of health only discovered the outbreak after they had left the state.

“As far as I can tell, individuals came to the wedding without following the appropriate travelers’ guidance,” Ms. Valley said. “The individuals involved with that had already left. So I don’t believe anybody was fined as a result of it because, unfortunately, with this type of thing, you find out about it after the fact when people start testing positive.”

The wedding, which was a combined indoor and outdoor event that took place on Oct. 11, did not violate any state or local orders regarding the size of gatherings, Ms. Valley said. Indoor events can have up to 25 people in attendance, while outdoor events can include as many as 100.

The Island has seen an increase in case numbers in recent weeks, capped by the six new cases reported on-Island Monday. At least 10 new cases have been reported on the Island since Columbus Day.

Ms. Valley said the cluster provided further context for the recent uptick in cases on the Island, and hopefully signaled that any further outbreak could be contained through contact-tracing.

“We can’t get complacent,” Ms. Valley said. “So far, we’ve been good about keeping the numbers down. But you can see it out there, there are more gatherings. People are taking less precautions. And this was a good reminder that you can’t do that.”

The press release also preached travel vigilance with future holiday weekends, like Thanksgiving, approaching.

“This cluster should serve as a cautionary note for families with college and university students who will soon be returning home for the Thanksgiving holiday. As noted below in the state guidelines, any student returning from a high-risk state must fill out the Massachusetts Travel advisory form prior to returning and be able to produce a negative test administered 72 hours before arrival,” the release states.

“Although this outbreak is unfortunate, the wedding is only one of many public gatherings held on the Island and should also serve as a reminder that we must remain vigilant in observing Covid safety guidelines.”