A security official said the warring Al-Marazig and Al-Saida tribes clashed on Tuesday in Maarib province, 170 km east of the capital Sanaa.
Bloody tribal clashes, sometimes involving security forces, are common in Yemen.
Although there was no confirmation as to what started the battle, tribal warfare in Yemen is often over the control of fields of Qat (a mild narcotic).
In addition, tensions between the government and various tribes periodically escalate into violent confrontations.
Various Yemeni tribes have been accused of kidnappings, shootings, revenge killings and other acts of violence.
It is estimated there are more than 60 million firearms in the country – an average of more than three per inhabitant.
Children, who are taught to use guns from an early age, are believed to be widely involved in tribal feuds.