What is the ruling on the severance of ties between a brother's wife and his children, and between a sister's children and the maternal uncle's children, as a result of disputes that led to the death of one of the parties, and the severance still continues?

Allah has made it obligatory to maintain kinship ties and forbidden their severance. Whoever falls into the severance of kinship commits a sin, as does whoever causes it. Efforts should be made to reconcile among people, for it is one of the greatest acts of nearness to Allah, as He states: {There is no good in much of their secret counsel save (in him) who enjoineth charity or kindness or reconciliation between people}.