Egypt's top Muslim cleric has stirred up controversy after saying that polygamy is an "injustice" for women.

Sheikh Ahmed al-Tayeb, Al-Azhar's Grand Imam, said "those who say that marriage must be polygamous are all wrong."

He said polygamy is restricted in Islam and requires fairness. "If there is not fairness it is forbidden to have more than one wife," he said.

He added that polygamy came from "a lack of understanding of the Quran and the tradition of the Prophet."

His comments, aired Friday on state TV, sparked a heated debate on social media, with some siding with scholars calling for a ban on the practice.

Al-Azhar sought on Saturday to clarify the comments, saying that al-Tayeb wasn't calling for a ban on polygamy.