The incident happened at around 12:17 a.m. on Padre Faura Street, near the entrance of the DOJ. No casualties were reported, police said.
Authorities immediately secured the area as the Philippine National Police Explosive Ordnance Disposal (PNP-EOD) unit responded to conduct a technical examination of the blast site.
The MPD told Manila Bulletin that an investigation is ongoing to determine the source, nature, and circumstances surrounding the explosion.
The situation has since been placed under control, with the DOJ compound remaining secure.
Officials assured the public that security measures in the area have been reinforced as authorities continue to gather evidence and assess the incident.