An ultra race with just six runners has been cancelled after organisers received "vile threats" amid concerns over the coronavirus.
Ultra Running Limited received more than 100 messages urging it to cancel Jogle 2020, which takes place between John O'Groats and Land's End.
Race director Steve Worrallo said he had felt "we weren't safe to continue".
One competitor, Michael Williams, said: "We were social distancing. You couldn't be more apart."
The 860-mile, 17-day event started on Friday.
Within the first three days, covering 131 miles up to Drumnadrochit in the Scottish Highlands, two competitors had dropped out due to injury.
On Sunday night, Mr Worrallo uploaded a race report, but was inundated with comments insisting the event should be cancelled.
"They were unsavoury, nasty and it gave me the impression we weren't going to be safe," Mr Worrallo said.
Mr Williams, 68, from Northampton, said he had been training for months to run the race for Pancreatic Cancer UK in memory of his sister, June Locke, who died from the disease in 2002.
The four remaining competitors had raised more than £16,000 for charity.
In a Facebook message, Mr Williams said: "Because of vile threats online to Ultra Running Limited this race has been cancelled."
He told the BBC: "We were warned not to go to the next stop at Fort William. We had physical threats, really abusive."
Comments were also posted on Ultra Running Limited's Facebook page.
One said it was "irresponsible and selfish" to be carrying out a race "during a highly contagious pandemic".
Another accused them of "stupidity and a callous disregard".
Mr Worrallo said runners had used hand sanitiser, support crews and hotel staff had been no closer than three metres to them at any point and anyone showing symptoms of coronavirus had been prevented from competing.
"It isn't as if we run as a group. Everybody is isolated," he added.