Hundreds of coronavirus test appointments have been cancelled due to a shortage of testing kits, it has emerged.
Test centres across the country were forced to close yesterday after medical staff ran out of vital medical equipment used to test for the virus.
Most testing sites, but not all, are expected to reopen today.
Those who were due to be tested yesterday have been given new appointments.
The country's largest test centres, Pairc Ui Chaoimh in Cork, and Tallaght Stadium, in Dublin, were both closed after they ran out of testing kits.
In Tallaght, people attending scheduled appointments were turned away when they arrived at the testing centre.
Several people who have potential symptoms of the virus and are in priority groups for testing turned up at the stadium only to be told their appointments would be rescheduled.
One of those involved said there was no sign or notification at the stadium and they only found out it was closed after contacting the HSE.
It is understood a text message alerting people to the cancellation of their test failed to send to some who were scheduled for an appointment in the football stadium.
The HSE sent another message apologising for the mix-up yesterday morning.
However, this came too late for those who had already made their way to the testing centre.
The HSE announced it was closing Pairc Ui Chaoimh due a lack of testing equipment.
The Cork testing centre is due to reopen today.
A Government source said the HSE is up to date on referrals in Cork and Kerry, and will offer appointments today for any outstanding referrals.
Following a series of queries, the HSE revealed testing had been scaled back, due to a lack of specialised testing equipment.
"There has been limited testing nationally today as the supply of testing materials has been limited, a further order is due in this afternoon and will be distributed," a spokesperson said.
There is a worldwide shortage in testing kits and the reagent used to test the sample from those thought to have contracted the virus.
A significant shipment of new testing kits and personal protection equipment (PPE) for healthcare workers to arrive yesterday evening.
More than €26m worth of PPE was delivered, totalling 1.6 million masks, 400,000 eye protections, 265,000 gowns and 254,000 gloves.
Almost 5,000 people are tested a day in Ireland for Covid-19 and more than 50 testing sites are being set up.
The HSE said there is backlog of 15,500 people waiting to be tested for the virus since the Government changed the criteria for receiving an appointment.
Around 10,700 people have received an appointment and 4,800 are waiting for a test date.
More than 33,000 people have been tested for the coronavirus since the start of the public health crisis.