The violence erupted on Saturday between members of the Nuba and Bani Amer tribes in the town of Gadaref, said Mohieddine Ahmed, governor of Gadaref Province.
"It all started when a woman from the Nuba tribe and a water vendor from the Bani Amer tribe quarreled over the price of water" on Saturday, Ahmed said, Presstv Reported.
"The verbal dispute ended with the vendor killing the woman, which triggered anger among her tribe members."
Members of the two groups then set fire to homes and shops belonging to each other's kin, Ahmed added.
"In the ensuing clashes, seven people have been killed and 22 wounded," Ahmed said, adding that the two groups have clashed in the past.
The wounded included seven policemen, he said, as officers sought to separate the groups with tear gas and by firing shots in the air.
Ahmed said the fighting that erupted on Saturday continued until Sunday morning.
Tribal clashes are often reported in several regions of Sudan, especially in the war-torn western Darfur provinces.
Sudan, an ethnically diverse country, has been rocked by nationwide protests since December last year that led to the ouster of longtime leader Omar al-Bashir on April 11.
Thousands of protesters still remain camped outside the military headquarters in central Khartoum, calling on the army generals who deposed Bashir to hand power over to civilians.