For the first time direct fighting erupted Sunday between Republican Guards and the First Armoured Division in the capital Sana'a, leaving a citizen and a soldier dead, DPA reported.
Sporadic attacks using heavy military equipment continued for about three hours, a few kilometres from a protest camp in al-Tagheer Square in Sana'a, a local source told the German Press Agency dpa by telephone.
A soldier affiliated with the First Armoured Division of the defected commander Ali Mohsen al-Ahmar was killed, in addition to a citizen living in the area of Shamlan where the confrontation took place, according to the source.
Tens of thousands of demonstrators took to the streets of Sana'a Sunday, denouncing pro-government attacks on civilians in Arhab and Nihm districts in Sana'a as well as Taiz governorate.
Sunday's march was "to further push the regime to come to an end and to stop its aggressive on the Yemeni people," Waleed Al-Amari, 33, told dpa.
Protesters have carried out many demonstrations during the month of Ramadan to assert their demand for regime change, which they started mid-February.
The situation is tense, specially in Sana'a, as fighting surrounds the capital in the outskirts, blended with infrequent attacks by Saleh's forces against either al-Ahmar backers or Mohsen's troops just inside the capital.