NHS Highland is continuing to face "significant pressure" due to staffing shortages.
NHS Highland is suffering from a "significant" strain on resources amid staffing shortages just days after the health board pleaded with nurses to take on extra shifts.
A spokeswoman for the health board said there was "pressure across our systems" attributed to rising Covid-19 rates in the region.
The warning comes after a social media post asked for nurses to consider taking on additional shifts to cover the absence of others.
An NHS Highland spokeswoman said: "Significant pressure across our system remains.
"We are still experiencing a significant level of short notice staffing gaps, particularly in nursing, as a result of the ongoing high prevalence of Covid right across our local communities, which means many of our colleagues are not available to work their planned shifts.
"Patient safety is our priority while also ensuring our colleagues are supported during this very challenging time."
On Sunday a spokesman for the health board stated on Facebook: "Our acute hospitals are continuing to see an increase in pressure across the system and this has been exacerbated by a recent rise in Covid-19 cases after a period where the number of cases across NHS Highland was declining or plateauing.
"Covid-19 is also having a significant impact on staff absences particularly among our nursing staff in Raigmore Hospital. If any of our nurses at Raigmore are able to work any extra hours this evening or can cover any shifts on Monday then we would be really grateful if they could contact the ward they normally work in to see how they can help.
"We would like to thank all of our staff across NHS Highland for the amazing job they are doing to keep our services running."