She refused to give more detail, but said other people were also being investigated.
"Their case is linked with the March 15 blast but how it is linked and details on that will likely come out of the investigation," Zhiti said in a telephone interview.
Last week, the Prosecutor-General's office asked Parliament to lift the immunity of former defense minister Fatmir Mediu, accusing him of abuse of power, as part of an inquiry into the explosions.
In the March 15 disaster, a series of explosions at an ammunition disposal factory near the capital, Tirana, killed 26 people, injured 302 and destroyed or damaged some 5,500 houses.
Mediu - the leader of the Republican Party, which is part of the governing coalition - has denied wrongdoing.
The Parliament is expected to discuss lifting Mediu's parliamentary immunity later this month.
The Socialist-led opposition has accused the government of corruption in the disposal of obsolete weapons, and urged Prime Minister Sali Berisha to resign.
About 100,000 tons of excess ammunition, mostly Russian and Chinese artillery shells made in the 1960s or earlier, are stored in former army depots across Albania.
The United States on Friday offered help from contractor ArmorGroup North America (AGNA) to begin the slow and dangerous process of removing live munitions from the GJerdec blast area, according to a statement by the U.S. embassy in Tirana.
The embassy urged displaced residents not to return to the blast area until it was judged safe.
NATO members, including the United States, Canada and Norway, have been helping Albania dispose of the arsenal.