The governor of Aswan has announced a three-day truce in fighting between rival tribes.
Mustafa Yousri said the truce between an Arab clan, Bani Helal, and a Nubian tribe, Daboudiya, would last for three days.
The truce was agreed at a reconciliation meeting.
Al-Azhar Grand Imam Ahmed El-Tayeb will play a role in further reconciliations talks during the truce, Yousri added.
Any breach in the truce will lead to a response from the army and security forces.
Each tribe has formed a committee to ensure the truce is applied.
Those responsible for the violence, which has killed 25 people, will be brought to justice, Yousri vowed.
There will be military and police patrols in the districts where the clashes have taken place.
Tensions began on Wednesday over the harassment of a girl and offensive graffiti.
The fighting killed 25 and injured 56 others.
Revenge killings are commonplace in southern Egypt, often over perceived honour-related issues.
On Saturday, interim Prime Minister Ibrahim Mahlab and Interior Minister Mohamed Ibrahim travelled to Aswan to mediate a truce.
Violence resumed on Sunday, killing two.