COTABATO CITY -- (UPDATED) An explosion transpired at Mother Barangay Rosary Heights in this city at about 9 p.m. Sunday.
Initial reports said a hand grenade exploded outside the house of Judge Rosalito Rasalan.
Another hand grenade was lobbed at the roof of Rasalan's house.
The family believe the explosion is connected to Rasalan's job as a judge.
Cotabato City Secretary to the Mayor Boy Rasalan also said the blast is not likely connected to the plebiscite.
However, he said the incident may bring fear to the residents in the area.
The explosive ordnance disposal team is already conducting post-blast investigation.
No casualty has been reported.
Authorities continue to conduct a deeper investigation.
Cotabato City is one of the areas where the January 21 plebiscite for the ratification of the Bangsamoro Organic Law will be held.