The semi-governmental National Council for Human Rights (NCHR) said Wednesday that Egypt's constitutional referendum saw a high turnout and that its transparency was not negatively affected by reported violations.

The vote, the first poll since the July 2013 ouster of Islamist president Mohamed Morsi, and the sixth national vote since the 2011 popular uprising that deposed president Hosni Mubarak, has been billed by authorities as the first milestone towards new democratic rule.

Preliminary results show Egyptians overwhelmingly endorsed the new charter, with an approval rate exceeding 90 percent at several polling stations across the country, state-owned news agency MENA and government officials said.

The poll appeared to be a public vote of confidence in army chief General Abdel-Fattah El-Sisi and the interim government's transitional roadmap.

The result is expected to smooth the path for El-Sisi's candidacy for the presidency, as public pressure for him to run for head of state increases.

Polling on Tuesday, the first day of voting, was higher than that on the second and final day, with a discernibly high turnout of women and the disabled, the (NCHR) said in a Wednesday report on the two-day vote.

Many authorised observers, including several members and researchers of the NCHR, were barred from supervising the polling, the report revealed. Many permit-holding journalists were also banned.

The watchdog urged that the country's problematic voters database be improved before upcoming presidential and parliamentary elections take place. Some voters found they were not registered and could not vote.

The NCHR's monitoring team did not receive reports about serious breaches affecting the fairness or transparency of the poll, the rights group said.

The voting process was marred, however, by numerous attempts to influence the ballot, through barring voters from voting or directing their choice, and rumour mongering about potential bombings, violence, or stretching the vote into a third day, the report added.

The rights watchdog is expected to issue an in-depth report on the polling process as well as the legislative and political environment surrounding the poll in a few weeks.