Exam officials on Friday said invigilators would no longer be using an app to check attendance records of students sitting university entrance exams from Saturday, after the app failed twice in the past two days.

The Examinations and Assessment Authority said candidates could still use a separate app to mark their attendance, but invigilators would be working manually from now on.

The authority's secretary general, Wei Xiang-dong, said they had upgraded the system after the "i-Invigilation" app experienced the first glitch on Thursday, but the issue persisted.

"It will take some time to fix the problem and we don't want it to affect the following exams," he said.

The authority said it is also looking into why the glitch happened even though they had done a stress test on the HK$9-million-system with "promising" results.

Wei said the change should not affect students since only the invigilators would be doing more work.

Invigilators will use paper forms to take attendance and count answer papers manually, just like before the authority switched to the digital system.

Some of them said they were unable to log into the "i-Invigilation" app ahead of the Chinese and English language exams on Thursday and Friday.