In a statement issued through his spokesman, UN Secretary General Ban Ki-moon said he was "saddened" over the brutal killing, even as he condemned the "heinous crime."
"The Secretary-General is saddened by the reports of the brutal killing of more than 40 civilians in the Maguindanao province, Southern Philippines. He condemns this heinous crime committed in the context of a local election campaign," the statement read.
Ban also extended his "condolences" to the families of the victims and hopes that "no effort will be spared to bring justice and to hold the perpetrators accountable."
Likewise, ambassadors to the Philippines have made known their condemnation and abhorrence of the November 23 massacre.
British Ambassador Stephen Lillie issued on Wednesday a statement of condemnation, with the hope that "authorities in the Philippines will take urgent action to bring the perpetrators to justice and prevent further escalation of violence in the run-up to next year's elections here."
According to Lillie, "effective action" by the Philippine government is crucial for the British government to maintain confidence in the country.
In an interview with GMANews.TV, US Embassy deputy spokesperson Woosie Mazengia said: "We condemn such acts of violence in the strongest possible terms."
Mazengia also said that the US government is extending its condolences to the families of those killed.
Visiting Indonesian Foreign Minister Dr. Marty Natalegawa said their government feels for the Philippines’ tragedy and hopes the perpetrators will be brought to justice as soon as possible.
“As a decent human being one cannot help but feel a sense of abhorrence," Natalegawa told reporters at a press briefing in Manila.
“Any senseless killing, any senseless violence we condemn in the strongest possible term," he added.
In 1996, Indonesia facilitated the peace talks between the Philippine government and the Moro National Liberation Front (MNLF) in Mindanao. Natalegawa was, however, mum over questions whether such agreement could be facilitated by Indonesia for clan wars.
Meanwhile, Shigehiro Matsuda, third secretary from the Japanese embassy, said Japan is quite concerned with the security over Mindanao.
Matsuda said the Japan International Cooperation Agency and several non-governmental organizations in Janpa have projects in Mindanao.
"Japan is really sorry for the incident, but we hope the incident does not affect projects in Mindanao," Matsuda told GMANews.TV.
The massacre took place a few hours after around 50 gunmen allegedly led by Andal Ampatuan Jr., the mayor of Datu Unsay (a municipality in Maguindanao province), and a police officer later identified as Chief Inspector Sukarno Dicay seized members of a large convoy of supporters of Buluan Vice Mayor Esmael Mangudadatu, an Ampatuan clan opponent who wants to run for governor.
The convoy of Mangudadatu supporters, accompanied by journalists, was on its way to an electoral bureau headquarters to file documents related to his candidacy, which the gunmen wanted to prevent.
The fatalities included Mangudadatu’s wife, sister and other relatives.
Following the tragic killing of at least 12 journalists in Maguindanao, the Philippines has now dislodged Iraq as the most dangerous place for journalists in the world, the International Federation of Journalists said.