BOSTON (CBS) — A prayer vigil was held by striking Tufts Medical Center nurses Sunday night.

Earlier in the day, Tufts Medical Center officials said Boston Police had to be called to the hospital after a “violent attack” by striking nurses protesting outside.

Tufts management called the incident “reprehensible, violent, and very disturbing.” Chief Nursing Officer Terry Hudson-Jinks said there have been incidents of Massachusetts Nurses Association supporters attacking buses that are trying to bring replacement nurses to work.

“At a couple of the hotels where the replacement nurses had been staying, there were protesters shouting profanities, pounding on the buses, throwing coffee, and really trying to intimidate the nurses within the buses that we count on,” she said. “Thankfully, all those nurses did arrive here in time to care for our patients.”

State Police offered a different side to the events.

They stated that they were called by hotel management around 5:45 a.m. for “a group of protesters picketing outside the hotel without a required permit. Troopers responded and confirmed that the 22 protesters indeed did not have a required permit for protest activity. We spoke to the protestors and informed them that they could not demonstrate without a permit. The protesters were cooperative and dispersed without incident.”

Dave Procopio, State Police Communications Director said that there was no violence, or throwing of any objects, including coffee. It took about fifteen minutes for troopers to clear the scene.

Sunday marks day 5 of the nurses’ strike–which was initially a walk-out and is now a lockout.

It’s the first nurses strike in Boston in more than 30 years.

“We condemn this behavior and ask that leaders who know that Boston is better than this to speak out against this dangerous activity,” the hospital said in their statement.

The Massachusetts Nurses Association said in a statement that they “have been focused on and dedicated to maintaining a peaceful picket line throughout these last several days,” and said they didn’t know about Sunday morning’s incident, which they say involved outside organizations, until after local media reported on it.

“In being made aware of this situation, we want to express that the MNA does not advocate the use of violence,” the statement read. “It is dedicated to meeting the needs of patients throughout the Commonwealth by caring for and protecting them, be that at Tufts Medical Center or in community hospitals on the other side of the state. That has not and will not change, and we will continue with our peaceful picketing and family-centered activities as we head into the final 24 hours of this forced lockout.”

#MNA says it was unaware that supporters of #TuftsNurses tried to intimidate replacement nurses. Says union does not condone violence. #wbz — Kim Tunnicliffe (@KimWBZ) July 16, 2017

Hudson-Jinks said she doesn’t think the MNA nurses would have participated in the incident.

“What I do know, there were MNA placards being held by these protesters,” she said. “We would like to ask everybody to stop, to cease and desist.”

She said the hospital has increased security around the buses that bring the replacement nurses to Tufts Medical Center.

“I don’t know one nurse that would attack another individual or another nurse,” one striking nurse said to WBZ-TV. “That’s not what we are about. We were unaware of the incident, I can’t really comment on something that I don’t know the details about.”

WBZ NewsRadio 1030’s Kim Tunnicliffe reports