Is it permissible to increase the blood money (Diyya) in cases of unintentional killing, or is the increase specific to intentional and semi-intentional killing, knowing that there are cases where the blood money is increased in unintentional killing as mentioned in some narrations (Athar)?

No evidence or scholarly opinion has been found to clarify whether the default principle for blood money (Diyya) is mitigation or aggravation, but it appears that the default is non-aggravation. The reasons for aggravating blood money, although scholars differ on them, are: intentional or quasi-intentional killing, killing within the Haram (definition) (sacred precinct), during the sacred months, or killing a relative (dhi rahim) or a prohibited degree of kinship (mahram (definition)). The Shafi'is and Hanbalis hold that blood money is aggravated when the killing occurs in the Haram, or against a person in the state of ihram (definition), or during a sacred month, or when killing a relative. The Hanafis, however, do not believe in aggravation in any of these cases. As for the Malikis, they consider blood money aggravated in intentional killing if the guardian of the victim accepts it, and in a parent killing their child. The aggravation of blood money can be by increasing its quantity (a Diyya and a third), or by its description, or by expediting its payment, or by making it payable from the killer's wealth. Uthman ibn Affan (may Allah be pleased with him), in a similar incident, ruled for the aggravation of blood money, making it a Diyya and a third, which Al-Albani authenticated.