Soldiers killed in blasts show military not remiss in securing Jolo Cathedral —AFP

The military committed no security lapse at the Our Lady of Mount Carmel Cathedral in Jolo even after two explosions tore through the biggest Catholic church in Sulu on Sunday, the Armed Forces of the Philippines has said.

The bombing, according to Brigadier General Edgard Arevalo, was not an indication that the military neglected its job.

"The AFP may have foiled 99 out of 100 attempts; but a singular successful try doesn’t mean government security forces have been remiss of their job," Arevalo said in a statement.

"The fact that five soldiers, now six, made the ultimate sacrifice during the blast prove that they religiously performed their level best to protect and rush to the rescue of the victims of the blast," he added.

Interior Secretary Eduardo Año a day after attack said the explosives slipped past the security cordon at the cathedral.

"Hindi pa natin nabubuo yung buong picture. Ang masasabi lang natin nakalusot yung dalawang bomba sa security protocol natin," Año said.

Año, a former chief of the Armed Forces of the Philippines, said security measures had been imposed at the cathedral because it had been under threat for some time.

"Because of the threat since last year, nagkaroon na tayon ng nagbabantay diya sa gate ng cathedral," Año said.

Six of those killed were the soldiers tasked to provide security at the church.

Following the twin explosions at the church, Jolo has been put under lockdown with beefed up security inspections among those who enter and exit the town.

Arevalo called on the public to cooperate with the authorities' tightened security measures, especially the PNP's new regulation prohibiting MRT and LRT passengers to bring any kind of liquid onto the train stations.

"We implore the collaboration of the citizenry. These measures may entail discomfort or inconvenience to us, but we have to do our share of sacrifices in the name of collective security and common good," the AFP spokesperson said. —Jamil Santos/NB, GMA News