Numerous scheduled cancer surgeries have been cancelled in Belfast to free up staff dealing with increasing Covid inpatients.
"Regrettably, the Belfast Trust has made the difficult decision to cancel some cancer-related procedures which we are currently working to reschedule as soon as possible," said the Belfast Health and Social Care Trust in a statement.
"Covid-19 admissions continuing to rise has put increasing pressures on hospitals, which led to the trust taking the extremely difficult decision to cancel surgeries in order to expand our support teams caring for Covid-19 patients.
"We do not underestimate the anxiety and distress this causes patients and families affected and we sincerely apologise for this."
Last week, the trust announced that around 100 non-urgent planned procedures were being rescheduled as part of efforts to re-orientate services to deal with the latest surge in coronavirus admissions.
On Wednesday evening, the trust confirmed that a number of surgeries had been cancelled, which the trust's medical director said was a "direct result" of people not getting the Covid-19 vaccine.
Dr Chris Hagan added that about 24 patients were affected. He told BBC's Good Morning Ulster: "Last week we were sitting with about 50 Covid patients in our hospitals, that has now risen to over 100.
"There is enormous pressure on our intensive care units with 10 patients in our intensive care, seven of whom are ventilated.
"This is a direct result of rising infections in the community due to unvaccinated people in the community," he said.
"I think it is really important that we get that message across that not taking up vaccine is driving infection in the community and that choice not to get vaccinated is then leading on to direct effects like this."
He added: "I just want to apologise that we have had to do this, it is a terrible thing to have to cancel people who are expecting surgery, at the last minute.
"But I want to reassure the public that we will try and reschedule all these operations as quickly as possible."
On Thursday, another 1,471 positive coronavirus cases were reported by the Department of Health - down from 1,600 on Wednesday.
This includes samples taken in recent days, not necessarily in the past 24 hours.
Two further deaths were also reported.
