Security was heightened in the southern Philippines Friday following a bombing that killed at least three people and injured nearly 30 others. Authorities suspect one of the Muslim separatist groups operating in the area is responsible.
Philippine police are seeking to question three men who were seen running from the market in Koronadal where the bomb went off Thursday.
A man claiming to be from Abu Sayyaf, a group notorious for kidnapping and extortion, called the mayor of Koronadal to take responsibility for the bombing. But authorities dismiss the claim as bogus.
Regional police commander Manuel Raval says the bombing has all the hallmarks of the Moro Islamic Liberation Front - the MILF. Philippine authorities blame the MILF for a bombing in May that killed 10 people in Koronadal.
But MILF spokesman Eid Kabulu categorically denies his group is involved in either bombing. He condemns Thursday's bombing as a "heinous crime" and called for a complete investigation.
"The MILF will not gain any benefit out of this incident," he said. " And so we want this incident to be investigated thoroughly. We are very interested to know who are the perpetrators or the group behind this incident because eventually it hurts, really, the effort to resume the former peace talks between the government and the MILF."
The government and MILF are trying to restart stalled peace negotiations aimed at ending the rebel's 25-year separatist insurgency on the island of Mindanao.
Mr. Kabalu suggests the bombing might be the work of opponents of the peace process.
"We believe this is part of an effort to, if not sabotage, somehow to derail the peace process," he said. "You know, there has been a positive development throughout this effort. And so we look at this as sabotage, really, to the effort by both the MILF and the government to resume at the earliest possible time the peace talks."
Speaking in Koronadal Friday, President Gloria Macapagal Arroyo said the bombing will not deter the government from preparing for peace talks, unless the MILF is found to be involved in the attack.