He said that out of 1.19 million people in the state who are aged 21 and above, there are still 312,070 who have not registered as electors.
"I am advising them to register quickly; there is still time because the electoral roll will only be gazetted in May," he said.
Abdul Aziz also announced that vote-counting process would only begin at 4pm for the polling centres which closed early.
"In the previous election, the ballot papers were counted as early as noon at several centres including in the Kinabatangan and Pensiangan parliamentary constituencies in Sabah," he said.
The latest move was important, he said, to prevent the possibility of a result leak, and certain people using the information to launch a psychological war.
"This is a new challenge for the EC in the era of the social media and speedy communication such as Facebook, Twitter and short message system," he said.
When asked whether the EC is proposing to ban the use of mobile telephones at vote-counting centres, Abdul Aziz said at the moment the commission has not made any decision to enforce such regulation.