Councillors fear a shortage of ambulances in the north is putting patient safety at risk.
Mercy chiefs have admitted demand has sometimes exceeded supply in and have vowed to try to find a solution.
Changes to maternity provision in the area following the death of a baby at Caithness General Hospital mean the trigger point for sending expectant mothers to Inverness has been lowered.
But the overall number of ambulances in the area has not been increased – leaving the service stretched.
There are only three crews on duty during the day – and two at night – covering the whole of Caithness.
Scottish Ambulance Service head of service for the Highlands, Graham Macleod, revealed yesterday there had been occasions when demand exceeded supply.
But he also tried to offer reassurance the service had been “operating and managing” with the resources available.
The maternity service at the Wick hospital has been under review since October after the “potentially avoidable” death of a newborn.
That has resulted in more mums-to-be being taken to Raigmore in the Highland capital, which has more advanced paediatric facilities.
Mr Macleod told the local authority’s communities and partnerships committee yesterday: “What I can say is that transfers have increased and we are in discussions with Caithness General about that.
“Not all are taken by road and we have an agreement with the air ambulance that they will assist us if we get a number of transfers coming together that we can’t deal with or cope with.”
He confirmed there was 24-hour cover between Wick and Thurso with a minimum of two ambulances on call.
And he added: “The demand has at points exceeded those two vehicles, and sometimes we’ve had five or six transfers waiting, but the air ambulance has played its part in that.
“We are working with NHS Highland to see if we can find some way of at least temporarily increasing the number of vehicles until we find out what the outcomes are going to be.
“But, at this stage, we are operating and managing with the number of vehicles we have got.”
The issue was raised by Wick councillor Gail Ross, who said members of the public had voiced concerns about ambulance provision.
She said she was “reassured” that the service was coping, but would still seek talks with NHS Highland and mercy bosses about the long-term provision.
She added: “I have to say I’m a bit shocked and will be seeking further assurance from them and NHS Highland.
“It’s an unfortunate situation that expectant mothers are having to travel long distances anyway and we need to deal with that.
“We need to make sure that we have sufficient access for both ambulances and patient transport vehicles.”
Caithness councillor Gillian Coghill said following the committee meeting that she had been unaware of the issue.
She added: “It’s very worrying and I am going to try and get clarity on exactly what the situation is.
“It’s not safe and it doesn’t instil confidence when you hear things like that.”
Asked if she thought lives could be at risk, she said: “There is always that possibility.”
Ward colleague Councillor Matthew Rhind described the situation as “very alarming”.
Caithness SNP MSP Rob Gibson said: “With the numbers of people having to travel to Raigmore, this should have been considered.
“I am prepared to write to NHS Highland and the ambulance service to try and resolve this speedily.”