Egyptians have voted in a key referendum on constitutional changes, which the opposition criticise as paving the way for a police state.
Some polling centres have seen just a trickle of voters
The information minister put turnout at between 23% and 27%, but unofficial estimates were much lower.
The 34 amendments include a ban on the creation of political parties based on religion, and sweeping security powers.
The government says the changes will deepen democracy, but opponents say it will be easier to rig future elections.
Some independent groups monitoring the poll put the turnout figure at 5% or less.
They say that voting stations stood empty for most of the day in many places, and that in some areas the authorities bussed in public sector workers and government employees to ensure a reasonable turnout.
But correspondents say there has been little sign of the "millions of voters heading to ballot boxes" reported by the official news agency, Mena.
The BBC's Heba Saleh in Cairo says that if voters stayed away it was not because of opposition calls for a boycott but because Egyptians feel their votes do not count.
"What's the use? All referendums are fixed," said one taxi driver quoted by AFP news agency.
"Egyptians know what's going on but we can't say anything or we'll be arrested and put in jail," he added.
Bans political activity/parties based on religion
Removes judicial supervision of elections
Invokes special powers to fight terrorism
Under Egyptian election laws, a low turnout would not affect the outcome, as a simple majority of votes cast is required for victory.
The government says the changes will allow the drafting of a new anti-terrorism law to replace the emergency legislation in place since 1981, giving police wide powers of arrest and surveillance.
In addition, the amendments ban all religious-based political activity and parties, a blow to the Muslim Brotherhood - an Islamic party banned in Egypt which represents the strongest opposition force.
They also allow the adoption of a new election law and do away with the need for judicial supervision of every ballot box.
Voting began at 0600 GMT and ended at 1700 GMT, although a number of the country's 10,000 polling stations were reported to have opened late. About 36m people are registered to vote.
Hundreds of riot police were deployed in Cairo.
Opposition lawmakers say the changes will undermine basic rights
Our correspondent says for many in the opposition this is a black day in Egypt's history as they say the changes spell the death of the constitution as the main guarantee of liberties and democracy.
The opposition says the changes will consolidate dictatorship, and that watering down judicial supervision of elections will make fraud easier.
They are also deeply uneasy about the wording of the articles on the new anti-terrorism law because it will be possible to bypass the constitutional guarantees protecting basic freedoms.
Human rights group Amnesty International has called the changes the greatest erosion of human rights in 26 years.