Two types of explosives were unearthed by construction workers at the Manila City Hall on Monday afternoon, according to a report.

RH 29 Boy Gonzales reported that the grenades were discovered during the excavation of the hall building quadrangle for a drainage project, and promptly reported to the City Security Force (CSF) and Special Mayor's Reaction Team (SMarT) Chief LtCol. Edward Samonte.

Authorities immediately contacted the Explosive Ordinance Division of the Manila Police District - Special Weapons and Tactics (MPD-SWAT), who carefully removed an MK2 grenade, known as “atis,” and placed it in a pail of water, as the explosive may still detonate.

They are currently determining the type of explosive the second bomb might be.

It is believed that the explosives were buried in the site during the second World War, according to an initial investigation.