No one was hurt but the blast damaged the red Nissan Frontier of regional DepEd officer-in-charge Leovigilda Cinches.
Cinches husband, Silvino, is the Central Mindanao director of the National Bureau of Investigation.
The attack occurred about a month after the ARMM Regional Legislative Assembly (RLA) asked Cinches to shed light, during a legislative inquiry, on the unremitted contributions of thousands of teachers to the Government Service Insurance System (GSIS).
In a report, the police said a motorcycle-riding man was seen in the vicinity of Cinches residence, located near the city engineers office, before the blast.
The regional DepEd has long been the subject of controversies because of teachers complaints about the non-remittance of their GSIS contributions and the non-payment of their salaries and fringe benefits.
ARMM Gov. Parouk Hussin, who is helping oversee the operations of the regional DepEd, earlier said his administration merely inherited the problem from past regional administrations.
Last month, the 24-member RLA, in an inquiry, revealed that GSIS contributions of ARMM teachers amounting to some P60 million have not been remitted.