Gunmen in plain clothes on Saturday opened fire on anti-government demonstrators in Taiz, southern Yemen, wounding at least 15 people.
The snipers shot at protesters calling for the ouster of President Ali Abdullah Saleh, who has ruled the country for over three decades.
Protests against his rule began in January. Since then at least 170 people have lost their lives.
The Associated Press reported on Saturday that gunmen killed six soldiers and wounded a seventh in the town of Radda in central Yemen.
The fresh violence comes one day after security forces shot and killed three people in Ibb, south of the capital, Sanaa.
Saleh remains defiant that he will not quit following the breakdown of a mediation deal brokered by six Gulf states.
It offered the 65-year-old immunity from prosecution in exchange for his resignation but the Yemeni leader refused to sign.
Qatar, one of the six mediators, had now withdrawn from the talks, accusing Saleh of “indecision and delays.”