The search for two experienced climbers missing for several days in the Scottish Highlands has been suspended for the rest of the weekend due to "increasingly hazardous weather" and a continuing risk of avalanches.
A 26-strong search team braved severe sub-zero temperatures, high winds, falling snow and limited visibility on Saturday in a bid to find Rachel Slater, 24, and 27-year-old Tim Newton.
The couple, from Bradford, West Yorkshire, failed to return from an outing on Ben Nevis last weekend, and treacherous conditions have hindered air and ground searches on Britain's highest peak in recent days.
Police confirmed that there have been no positive sightings resulting from Saturday's efforts and said searches have been suspended for Sunday. Officers hope the conditions will pick up again on Monday or Tuesday.
Both Ms Slater and Mr Newton's families have been kept informed of the developments.
Meanwhile, police were looking into reports that two other climbers had got into difficulty on Ben Nevis. It is understood the pair contacted police themselves on Saturday evening.
Few details are available about the climbers or the incident, which is believed to be a separate case from the search for Mr Newton and Ms Slater. A police spokesman said: "We are currently trying to locate a couple of climbers who have got into difficulty."
High winds and driving snow led to the search for Ms Slater and Mr Newton being suspended on Friday, and the Met Office issued snow and ice warnings for much of northern Scotland over the weekend.
But members of Lochaber Mountain Rescue Team (LMRT) were able to resume their work on Saturday morning.
In a statement issued on Saturday night, Police Scotland said: "The weather today was very poor with high winds, falling snow, limited visibility and a considerable risk of avalanches.
"Sadly, there were no positive sightings today and searches have been suspended for tomorrow due to increasingly hazardous weather and further risk of avalanches.
"Reviews continue to be ongoing and it is hoped that there will be an improvement to the conditions on Monday or Tuesday.
"Both Rachel and Tim's family continue to be appraised of these circumstances."
Search teams said their thoughts continue to be with Ms Slater and Mr Newtons family and friends.
An earlier posting on the LMRT Facebook page said conditions for the team were "extremely challenging" with a considerable avalanche risk, high winds and heavy fresh snow above 500 metres.
The temperature was around freezing at 500 metres and -6C (21F) on the summit, which felt like -19C (-2F) with the windchill factor.
They added: "We would like to thank everyone who has offered their assistance in the last few days.
"With conditions as they are we cannot afford to put any more people than absolutely necessary at risk and hope you appreciate why we have declined these generous offers.
Police have asked anyone with information, no matter how insignificant they may think it is, to contact them on 101.
Mr Newton was a member of Hinckley Mountaineering Club in Leicestershire before moving away to university.
Ms Slater is a graduate of Manchester University and is employed as an environmental consultant near Bradford.
She spent some time living and climbing in Canada, where her parents are still based.
It is believed the couple had been camping behind the Charles Inglis Clark memorial hut on the north side of Ben Nevis.
In a joint statement released on Thursday, their families praised the overwhelming response from members of the public and the climbing community.