The HSE has appealed to people to book appointments online for Covid-19 tests rather than just attending walk-in swabbing centres around the country.
It said the decision has been taken in order to reduce queues following an increase in demand, with "testing for the virus up 35% today and yesterday".
"To reduce queues, we would like people to book an online appointment rather than walk up."
Some walk-ins will be accepted, but people are being advised to book online "to speed up the process at the centres".
The HSE said "online self referrals remain open and capacity has been extended to meet 20,000 a day demand".
"We expect anyone who wishes to get tested can get a test same day, depending on what time they book."
The HSE said the appeal for people to make appointments is not aimed at reducing demand as there is capacity for over 20,000 tests per day but instead the move is "designed to reduce queues from walk-ins".