As the AC is a blood brother to Belsnia, as well as a member of good standing in the TP, it is safe to assume that Belsnia woud have informed the AC of any immediate hostile intentions toward Erinaum for the safety of its fellow Pact member. As the AC was not informed of any plans, it does not believe that the Belsnian government in any way engineered this tragedy.
Especially given that even before Atsnian rebels came out with any information regarding the incident, it offered to aid the Erinamese government in cleanup and medical aid, I believe that this is another one of mlochka's attempts to stir the pot and create some "real action", just like what happened in Sinai, and not some hostile action on Miko's part.