Alabama authorities have arrested two more people in connection with the mass shooting on Saturday at a Dadeville “Sweet 16” birthday party, a shooting that left four people dead and more than 30 injured.

The Alabama Law Enforcement Agency announced Thursday that Willie George Brown, Jr., 19, of Auburn and Johnny Letron Brown, 20. of Tuskegee, according to ABC News. They were charged with four counts of reckless murder, the same charges filed against Tuskegee brothers Ty Reik McCullough, 17, and Travis McCullough, 16, and 20-year-old Wilson LaMar Hill Jr. of Auburn.

The McCullough brothers have been charged as adults.

Officials said more charges are forthcoming.

“This is just the tip of the iceberg,” said Mike Segrest, district attorney for the Fifth Judicial Circuit of Alabama. “We’re going to make sure every one of those victims has justice and not just the deceased.”

Phil Dowdell, the 18=year-old brother of the birthday celebrant; KeKe Smith, 17; Siah Collins, 19; and Corbin Holston, 23, were killed in the shooting, as CrimeOnline previously reported. Four people remain in critical condition.

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[Featured image: L-R, KeKe Smith, Corbin Holston, Phil Dowdell, and Siah Collins/Facebook]