Tens of thousands of pupils underwent PCR tests across Abu Dhabi on Friday ahead of the new school term on Sunday.
Families queued at drive throughs and walk-in coronavirus screening centres across the capital.
Lengthy lines were seen throughout the morning but appeared to have shortened by early afternoon. Friday was expected to be one of the busiest days of testing to date.
All private school pupils in Abu Dhabi must take a coronavirus test ahead of the new school year, the authorities said on Wednesday.
Each of the emirates now have separate rules for school, and there are different rules for government schools as well.
On Friday - with just two days to go before school resumes - private schools in Ajman told parents that the authorities now require all pupils to have a negative PCR result to return on Sunday.