Philippine National Police (PNP) spokesman Chief Superintendent Joel Goltiao said the bomb, a mixture of nitrate and a yellowish powder, was earlier spotted wrapped in a garbage bag and placed in a box that was left in front of the Francisco Gold Condominium building along EDSA where the DILG main office is located.
Goltiao said a janitor found the package of explosives and immediately alerted a bomb squad of the Central Police District (CPD), which successfully defused it.
No group has claimed responsibility for planting the bomb. Goltiao said they still had no suspects or motives in the bombing attempt.
Police recovered from the scene a nine-volt battery, powered black-colored timer connected to a white-colored detonating cord with an improvised blasting cap.
The device was rigged to approximately six kilograms of a mixture of ammonium nitrate and yellowish powder. Other reports said the bomb was packed with a seven-kilo block of C-4 military explosive.
Chief Inspector Rodolfo Hernandez of the CPD SWAT team said they could not speculate on the extent of possible damage but bomb experts said the explosive could have caused substantial damage in the building had it gone off.
"The (bomb disposal) team who responded to the scene opened the box and detonated the bomb with the use of water cannon, which is part of our safety procedure because we cannot just touch and tinker with the box, it might explode," Hernandez explained.
Interior Secretary Jose Lina Jr. said the bomb was placed beside a concrete column supporting the building housing several offices of the department.
He said the device could have caused substantial damage had it gone off.
Lina suspected the bomb may have been planted by groups that wanted to take advantage of rising tension over the sluggish vote count by Congress, and sow chaos and probably destabilize the government.
"I appeal to Congress to finish the count to remove a situation that can be used by elements which want to destabilize our society," Lina said.
The bomb was discovered amid high security alert in Metro Manila following a rash of random bombings and shooting incidents which left four people wounded since Tuesday.
The latest incident also heightens tensions amid government warnings of possible "adventurist plots" by unnamed figures seeking to take advantage of a looming political showdown over the results of the May 10 presidential elections.
The PNP has placed its entire force on full alert since Saturday in a bid to head off any disturbance that may arise from the continued failure of Congress to proclaim the winner in the May 10 vote.
Goltiao said all leaves and days-off of police personnel in Metro Manila, Southern Tagalog and Central Luzon, as well as members of the Special Action Force, were ordered canceled to ensure their availability for anti-riot duties.
The entire force of the National Capital Region Police Office (NCRPO) in Metro Manila still remains on full alert on reports that supporters of opposition presidential candidate Fernando Poe Jr. are gearing up for mass actions.
Police have revealed the supposed timetable and various activities of several militant groups for this week until early next month.
Unconfirmed rumors have circulated in recent days on plans of some ranking military officers to stage a power grab on July 1.
Malacañang has dismissed the rumors as mere "coffee shop talk."
Defense Undersecretary Ricardo Blancaflor said a waiter found a package containing the explosives composed of ammonium nitrate "complete with detonating accessories" at around 2 p.m. in front of the DND canteen.
The finding was being investigated upon orders of Defense Secretary Eduardo Ermita.
Blancaflor downplayed any threat posed by the discovery, pointing out that, except for the waiters, no one else was in the canteen or in the surrounding area.
"Maybe it was not meant to harm or kill," he said, noting also that the explosives were not even assembled.
The timing device contained in the package was not set and it was not even attached to the explosives, he said.
Blancaflor refused to give further details.
Bomb experts from the explosives and ordnance division (EOD) of Camp Aguinaldo were dispatched to the area.
The explosives were turned over to the EOD headquarters also in the military headquarters for further investigation.
Blancaflor said they will await results of the probe before making any conclusive statement. — With Christina Mendez