Two people were killed when tribal clashes flared for a third day in the southern city of Aswan, Egyptian security sources said.
At least 25 people have now been killed in the violence between members of the city's two big tribes, the Nubian and the Arab Beni Helal clans.
Gunfights broke out outside the local hospital and morgue on Sunday near the city's centre, a few kilometres from the tourist hotels and its commercial areas, the AP news agency reported.
An angry mob from the Beni Helal clan torched more Nubian homes on Sunday after collecting the bodies of their relatives to bury.
The attack pushed armed Nubians into the streets, sparking pitched gun battles.
Police struggled to break up the mob outside the hospital. A military helicopter flew over the area.
The renewed clashes came shortly after the local governor visited the area.
An AP photographer there said clashes broke out nearby, including outside the hospital and morgue.
An armoured vehicle was stationed outside the neighbourhood of narrow dirt roads. Authorities closed local schools over fears of renewed violence.
A few kilometres away in the city center, shops and bakeries were closed.
The bloody feud began after a fight last week between school students drew in adults, sparking the clashes that turned deadly on Friday. Police said the fight was over the harassment of a girl.
Witnesses said offensive graffiti written on the school walls fuelled the violence.
Security officials say members of the Beni Helal clan are involved in arms and drugs smuggling and are well-armed.
The fight took on a political overtone when the impoverished clan accused the ethnic Nubians of supporting the military, while the Nubians say the Arabs back ousted Islamist President Mohamed Morsi.
Locals meanwhile complained of the inability of security forces to halt the vendetta violence.
They said police were mostly absent from the streets, causing the violence to spread. The governor appealed for the military to deploy troops in the area.
Egypt's Prime Minister Ibrahim Mahlab and his interior minister visited Aswan on Saturday to meet local leaders to end the dispute.
Mahlab promised a fact-finding mission to investigate how the violence erupted.
On Sunday, local government official, Mohammed Mostafa told private television station CBC that officials are considering emergency measures and possibly a curfew in the area.
Source: Al Jazeera and agencies