Violence flared across Syria ahead of a national referendum on a new constitution on Sunday.

On Saturday, at least 30 people were believed killed in regime shelling in three districts in the restive city of Homs, while another 40 were believed dead in the central province of Hama.

London-based rights group Syrian Observatory for Human Rights said six people were killed by security forces in clashes with army defectors in the Ezaz area of Aleppo province. Another seven were reportedly killed when regime troops fired on mourners attending a funeral procession.

Voting in the referendum, called by President Bashar al-Assad, began at 7:30 a.m. local time on Sunday, with polling stations open for 12 hours. The vote puts forward a constitution that its advocates say would open Syrian politics to pluralism and end the decades-long monopoly on power held by the ruling Baath Party.

The opposition has dismissed Assad's reform pledges as insufficient, and the US branded the plans for a referendum as "laughable" when they were announced.

'No concrete results'

Meanwhile, negotiations between the International Committee of the Red Cross (ICRC) and Syrian authorities aimed at the evacuation of civilians and two wounded Western journalists from the Baba Amro district of Homs failed on Saturday.

"The discussion has yielded no concrete result today," a spokesperson for the ICRC told AFP news agency, adding that "unfortunately, therefore, no emergency evacuation will take place today."

On Friday, the ICRC was able to evacuate 27 people, mostly women and children, when the bombardment of the area eased. But violence increased on Saturday in the district, as it entered a fourth week of shelling.

Disappointed with the outcome of the "Friends of Syria" meeting in the Tunisian capital on Friday, opposition activists said the world had abandoned the victims in Homs. Friends of Syria is a group of 60 countries that gathered for its inaugural meeting on Friday and called on Damascus to "immediately cease all violence" to allow humanitarian access.

"They [foreign leaders] are still giving opportunities to this man who is killing us and has already killed thousands of people," said Nadir Husseini, an activist in Baba Amro.

Countries attending the conference urged tighter restrictions and sanctions on Assad's regime, but ruled out military action.

dfm, rc, sb/pfd (AP, AFP, dpa, Reuters)