Egypt's President Abdel-Fattah al-Sisi has called on the woman attacked by a mob in a Christian village in Minya province not to be "angered" by what happened.

Speaking at the inauguration of a new housing project today, he condemned the sectarian attack and said those responsible would be punished.

The attack saw a 300-strong mob torch Christian houses and strip the 70-year-old woman naked as she was dragged along the street. It followed allegations that a Christian man – thought to be the woman's son – and a Muslim woman were involved in an relationship.

According to the Ahramonline news service, Sisi said: "When I address my speech to this woman I don't say this [Christian] Egyptian because we are all one.

"We are all Egyptians who are equal in rights and duties. It is not appropriate that what happened be repeated. Whoever commits an offense will be held accountable."

He said: "I call on this Egyptian lady not to be angered by what happened."

The attack has been widely condemned, including by the General Bishop fo the Coptic Orthodox Church, Bishop Angaelos, who said: "It is indeed shameful that such mob crimes can be perpetrated against innocent communities at all, of whatever faith or ethnicity, and especially as a result of slanderous and unsubstantiated rumours; and that an elderly mother could be so publicly and indecently humiliated."

He continued: "Egypt is at a formative stage of its contemporary history which requires a robust system of law and order that underpins an ethos of equal citizenship and accountability. Any such steps taken at the national level are severely hampered and undermined by these recurring failures at the local level."