EDMONTON -- The line at a drive-thru COVID-19 test site in Sherwood Park snaked down the road and around the corner Wednesday afternoon.

Many people waited upwards of three hours to be tested at the site, which does not contain public washrooms.

Alberta Health Services acknowledged "challenges" that led to delays at the assessment centre, but said it does not expect them to reoccur.

"There were a number of factors contributing to Wednesday's backup at the site, including an increased number of swabs and new staff being trained," AHS told CTV News Edmonton.

There were also people who joined the line without a referral, AHS said, so extra staff were brought in to process the long line.

AHS opened testing to anyone with COVID-19 symptoms Monday. On Tuesday, 2,853 were performed in Alberta, a steep increase from testing numbers in early April.

The increased testing will give health officials a more accurate understanding of the virus’ presence in Alberta.

AHS said it opened up a third assessment site in the Edmonton zone Thursday and is working to set up another drive-thru testing centre in the area to meet demand.

Only people who are referred after completing an online assessment can access the COVID-19 testing sites.