Another woman, 56, has passed away at Sofia's emergency Pirogov hospital, raising the dead toll in the shooting incident to four.

Ivan Kalukov, 67, passed away overnight in Sofia's Military Medical Academy from self-inflicted gunshot wounds.

The 56-year-old woman is the mother of another female victim, 28.

Kalukov is a former army officer.

The incident was sparked Monday by an argument between him and a Roma family living in a trailer near his house.

The Roma have set a tire ablaze to celebrate the beginning of Easter Lent by following the rite of jumping over fire, which had irritated Kalukov. He attacked young Roma man Kiril, 26, hitting him with a hubcap.

Kalukov then returned inside his house only to come back moments later, burst in the trailer and start shooting haphazardly, murdering Kiril on the spot and injuring three more. One of them, the 28-year-old female, passed in the hospital later Monday.

Upon returning home, the attacker shot at himself, and was also hospitalized in critical condition. Doctors were unable to save his live.