Unidentified attackers on March 8 opened fire on a minibus near the village of Saberio, killing three adults and a 6-year-old girl. Among the victims are two ethnic Abkhaz and two ethnic Georgians.
Sergei Shamba said the incident was aimed at "discrediting the authorities of Abkhazia and the Russian peacekeepers" stationed in the region.
Georgian officials have rejected the Abkhaz accusations and said Gali-based criminals were probably behind the shooting.
The commander of the Russian peacekeeping force, Sergei Chaban, said on March 9 that he would discuss the incident with representatives of Georgia, Abkhazia, and the United Nations.
Abkhazia won de facto independence from Georgia in 1993 after a 13-month war that killed thousands and turned an estimated 250,000 civilians into internally displaced persons.