Saudi Arabia may ban marriage for girls below 18, a government minister said after a case of an eight-year old girl marrying a man more than 40 years her senior drew international criticism and embarrassed the kingdom.

'Among the options that are available and excluding the issue of puberty, is to ban marriage for (people) under 18,' Justice minister Mohammed al-Eissa told Asharq Al-Awsat newspaper.

He was responding to a question about his ministry's plan to deal with the marriage of young girls. 'A girl below 18 is often not fit to take the family responsibility especially if she quickly gives birth (after marriage),' he said.

Saudi Arabia is a patriarchal society that applies an ascetic form of Sunni Islam which bans unrelated men and women from mixing and gives fathers the right to wed their sons and daughters to whomever they deem fit.

Many Saudi clerics, including the kingdom's chief cleric grand mufti Sheikh Abdul-Aziz Al al-Sheikh, endorse the practice of marrying underage girls, arguing that in doing so they avoid spinsterhood or the temptation of engaging in relationships outside the wedlock.

A 50-year old man in the small Saudi town of Onaiza agreed this week to divorce his eight year-old bride. Financial considerations could prompt some Saudi families to wed their underage daughters to much older men.

Many young girls in Arab countries that observe tribal traditions are married to older husbands but not before puberty.

Such marriages are also driven by poverty in countries like Yemen, one of the poorest countries outside Africa.-Reuters