Several others were wounded during clashes in Yemen's second city Aden as violence flares between pro-government fighters and those seeking an independent south.
At least eight civilians were killed and several others wounded on Friday during clashes in Yemen's second city Aden, a security source said, as violence flares between pro-government fighters and those seeking an independent south.
The fighting erupted on Wednesday and has continued unabated between the two sides, who are in effect backers of the Aden-based internationally recognised government of President Abd Rabbu Mansour Hadi.
One faction however is known as the Security Belt, a force trained by the United Arab Emirates, which is dominated by fighters who seek independence for southern Yemen.
On Friday, fierce clashes broke out between the two sides during which a mortar round crashed into a house killing six people, four of whom were from the same family, a security source said.
Twelve other people were wounded in the fighting, the source said.
Doctors Without Borders (MSF) tweeted Friday that it had treated 75 people in a hospital run by the charity "since yesterday (Thursday) night" including seven who were in a critical condition.
"Most of the patients we admitted are civilians and were injured by shrapnel during shelling on their houses or stray bullets," MSF said.
Aden is located in southern Yemen, which is largely controlled by loyalist forces.
Southern Yemen was an independent state until 1990 and the north is perceived to have imposed unification by force.
The UAE is a key partner in a Saudi-led military coalition which intervened in Yemen more than four years ago to prop up Hadi's government in the face of an uprising by Iran-aligned Houthi rebels.
The Huothis control parts of northern and western Yemen, including the capital Sanaa.