The Syrian government is holding a national referendum on a new constitution, amid continuing violent unrest and a boycott by the opposition.
The new constitution calls for a multi-party parliamentary election within three months.
The opposition has dismissed Sunday's vote as a farce and demands President Bashar al-Assad stand down.
The vote comes amid ongoing violence, with activists saying more than 80 people died across Syria on Saturday.
The government has pressed ahead with organising the referendum despite the unrest, setting up more than 13,000 polling stations for 14.6m voters.
State television has been holding discussions about the new document, which allows for more opposition to Mr Assad's Baath Party, and telling people how they can vote.
However, the constitution has been rejected out of hand by the opposition.
One group described the new constitution as fraudulent and the referendum as a farce.
It pointed out that the regime had never respected the old constitution, which enshrines freedom of speech and peaceful demonstrations and bans torture.
The BBC's Jim Muir in neighbouring Beirut says how the vote can plausibly be held in the current situation remains to be seen.
Turkey's Foreign Minister Ahmet Davutoglu echoed this view at a news conference in Istanbul, asking: "On one hand you say you are holding a referendum and on the other you are attacking with tank fire on civilian areas.
"You still think the people will go to a referendum the next day in the same city?"
The US has dismissed the referendum as "laughable".
Friends of Syria
The Syrian Observatory for Human Rights, a UK-based activist group, said Saturday's deaths included 24 civilians in the embattled city of Homs.
It said 23 government soldiers were killed in clashes with rebel groups across the country.
The Red Cross has been trying to evacuate more people trapped in Homs's Baba Amr suburb but admitted it had made no progress on Saturday.
Among those it is trying to help are two injured Western journalists, Edith Bouvier and Paul Conroy. It also wants to retrieve the bodies of another two journalists, Marie Colvin and Remi Ochlik, who were killed last week.
Hundreds of armed rebels from the Free Syrian Army are holding out in the suburb.
Meanwhile, international pressure is mounting on President Assad to end his government's 11-month crackdown on opponents.
Kofi Annan, the former UN secretary general who has been appointed the UN and Arab League's envoy to Syria, called for all parties to co-operate in finding a peaceful solution to the crisis.
On Friday a meeting of the "Friends of Syria" group was held in the Tunisian capital, Tunis.
Delegates from 70 countries issued a declaration calling on the Damascus government to end violence immediately, allow humanitarian access, and permit the delivery of relief supplies.
The UN estimated in January that 5,400 people had been killed in the conflict. Activists say the death toll now is more than 7,300.
The Syrian regime restricts access to foreign journalists and casualty figures cannot be verified.