Covid-19 testing capacity in Scotland is to be increased following a "major spike" in demand.
Nicola Sturgeon said three new mobile testing units would be deployed this week, with the first operational in Glasgow later on Tuesday.
The number of tests that can be carried out at regional testing centres will also be increased.
"Technical issues" with the test booking system are also being resolved, the first minister said.
On Monday, some people were being directed to centres in England or Northern Ireland after requesting a coronavirus test.
Ms Sturgeon said: "We have always known that there will be fluctuations in demand for testing. That's why we have contingency plans in place and these contingency plans are already being activated."
The three new mobile testing units will increase capacity by between 1,200 and 1,500 tests per day.
In addition to more testing being available at the UK government-run regional testing centres, Ms Sturgeon said additional capacity would be introduced at NHS Scotland facilities to manage local demand.
This will include drive-through testing facilities in NHS Greater Glasgow and Clyde area.
Eleven "walk-through" centres will also be introduced, adding capacity for another 3,000 tests per day.
The first of these will be opened in St Andrews in Fife, the first minister said.
"We will continue to implement these plans to further increase capacity as we head into winter, as we have always been preparing to do," she said.
"But we will also continue to work to ensure appropriate contingencies are in place for periods when we have higher than expected demand for testing."
Currently, an average of about 14,000 Covid-19 tests are being carried out each day in Scotland.
This includes tests by NHS Scotland and UK government labs, which operate the regional testing centres, care home portal and home tests.
In total, more than 480,000 people in Scotland have been tested for coronavirus since the outbreak began.
The first minister also acknowledged the issues some people had faced when trying to book a test, saying these had occurred across the UK following a "major spike" in demand for testing.
It has led to some people in Glasgow and the central belt being directed to Penrith in Cumbria for test.
Another woman, from Ayr, told BBC Scotland she had been told to travel to Belfast for her grandson's coronavirus test.
People living in England have faced similar issues, with one person from Ilfracombe in Devon being directed to a test centre in Swansea - a 350-mile (563km) round-trip taking more than six hours.
It is understood that some people in Newcastle have also been told to travel to Scotland for their test.
Ms Sturgeon said this "shouldn't be happening" and work was being carried out to fix the problem.
"Where any technical issues do arise - as, unfortunately, with a system of this scale and complexity they sometimes do - we will endeavour to have those sorted as quickly as possible," she added.