Philstar.com, citing information from the police, reports that "the same type of explosive was used in the January 23, 2012 blast in Makati and in the attack on a bus along EDSA, also in Makati, last year (January 25, 2011)."

The report noted: "An 81mm mortar shell also ripped apart a Newman Gold Liner bus along EDSA’s northbound lane, near the Metro Rail Transit’s Gil Puyat station in January last year. It left four people dead and 14 hurt. The explosion last January 23, 2012, on the other hand, happened at a vacant lot beside Salcedo Park, along H.V. de la Costa street. A car parked nearby was damaged but no one was hurt." Both incident Both blasts occurred at around 2 p.m.

According to reporter Aie Balagtas See,  Chief Inspector Jenny Tecson revealed in a phone interview, "Based on the reconstruction, it can be said that an 81mm mortar (shell was used in the H.V. de la Costa blast)." Tecson is the designated spokesperson for Task Group De la Costa, a special body formed to investigate the blast. The task group is composed of policemen from Makati, the Southern Police District (which supervises the city), and the National Capital Region Police Office.

Tecson further revealed that "a cellphone was used as the triggering device for the bus bombing, while they have yet to determine the device used for the De la Costa blast." Tecson added that it's "too early to tell" if the two incidents are connected to each other.

However, according to the report, "police have ruled out destabilization plots against the Aquino administration in both incidents, and said extortion could be the motive." In an interview over radio station dzBB, Director Leocadio Santiago, directorate for operations of the Philippine National Police, pointed out, "We are looking more on may nananakot (someone just wants to scare off his/her rival or the public in general) or extortion. It’s not connected with terrorism or any security threat."

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