Four people, including three children, were killed overnight when troops loyal to Yemeni President Ali Abdullah Saleh shelled a region north of the capital, hitting a petrol station, tribal sources said on Sunday.
Thirteen others were wounded in the attack in the Arhab area, some 40 km from Sanaa, where tribesmen have backed protesters demanding an end to Saleh's 33-year rule.
In the city of Taiz, south of Sanaa, a doctor said one civilian was shot dead and two were wounded by government forces who fired at a car. The incident occurred in a district where there have been clashes between government forces and pro-opposition tribesmen.
Months of anti-government protests have divided impoverished Yemen, pushing the Arabian Peninsula country to the verge of civil war and a humanitarian crisis.
Neighbouring oil giant Saudi Arabia and the international community fear growing lawlessness in Yemen is giving al Qaeda's regional wing scope to plan and potentially launch attacks in the region and beyond.
The ruling party is likely to name Saleh's deputy as its presidential candidate if a transfer of power is carried out under a Gulf-brokered power transition plan, Deputy Information Minister Abdu al-Janadi said on Sunday.
The General People's Congress intends to announce Vice President Abd-Rabbu Mansour Hadi as its candidate in the presidential election in the coming period, Janadi told reporters.
The U.N. Security Council issued a resolution on October 21 deploring the fighting and calling on Saleh to leave office in line with the transition plan.
Saleh has dug his heels in, surviving an assassination attempt and three times agreeing to sign the Gulf plan only to back out at the last minute.
Violence has showed no sign of easing.
In the southern port city of Aden, one soldier was killed and two wounded by a roadside bomb targeting their patrol on Sunday, a security official said. Islamist militants had probably planted it, the official said.
Soldiers, security officials and tribesmen fighting militants are frequently attacked in the country's south, where government control has been weakened by political upheaval.
(Reporting by Mohammed Ghobari in Sanaa and Mohammed Mukhashaf in Aden; Writing by Isabel Coles and Firouz Sedarat; Editing by Jon Hemming)