Lebanese police and a security source reported Monday that a Saudi citizen living in Lebanon was killed in the suburbs of Beirut and two of his brothers were arrested.

In a southern Beirut area controlled by Hezbollah, a Shiite group backed by Iran, the victim was stabbed to death in his home on Saturday.

Lebanon's Internal Security Forces said his brothers confessed to killing him "for family reasons".

The police identified the man only by his initials.

Waleed Bukhari, Riyadh's ambassador to Lebanon, expressed appreciation for the police's efforts to "uncover the facts and bring the perpetrators to justice" in a social media post on Sunday.

A Lebanese security source speaking on condition of anonymity said the victim married his brother's ex-wife and was killed in a fight over custody of the children.

The victim fought with his brother on Saturday to support his wife's custody request. According to the source, the brother then left his house and returned with their other brother to kill him.

He was born in 1980, while his brothers were born in 1976 and 1990, according to the Lebanese police statement.

Police said the incident occurred around 8:30pm (1730 GMT) in Dahiyeh, a bastion of Hezbollah.

According to the Lebanese security source, the victim lived in Dahiyeh, so he was at least tacitly protected by Hezbollah.