Violence erupted in Syria Sunday, as the polls opened for a vote on a new constitution likely to leave embattled President Bashar al-Assad with a lot of power.

Syrian state television aired footage from polling stations around the country and praised the government's decision to hold the referendum.

Critics have denounced the vote as a joke, saying Mr. Assad must relinquish power after an 11-month uprising against his autocratic rule.

President Assad promised the referendum in January, saying the new document would focus on creating a multi-party system.

On Sunday, activists reported explosions in the Baba Amr district of the central city of Homs, which Mr. Assad's forces have bombarded in recent weeks. Blasts were also reported in the northeastern oil city of Deir Ezzor and the central city of Hama.

The developments come after the Syrian Observatory for Human Rights said violence killed about 100 people Saturday, many in government attacks on opposition groups.

No independent confirmation of that account is possible.

Red Cross workers said they were not able to resume emergency medical evacuations Saturday for wounded victims trapped in Homs.

A spokesman for the International Committee of the Red Cross said talks with Syria's government and opposition groups produced “no concrete results” on Saturday. The ICRC spokesman said negotiations with both sides will continue Sunday in an attempt to enter the city and evacuate anyone in need of help.

A Red Cross spokeswoman told VOA the group is trying to get Syrian authorities to agree to a daily two-hour pause in the fighting so humanitarian workers can provide aid to victims.

U.N.-appointed investigators estimate the death toll from the uprising at 6,400 civilians and 1,680 army defectors. Syrian government officials have said they only took military action when under armed attack from “terrorists.”