JAKARTA, Indonesia - Police said they believe an Indonesian husband and wife, who had taken part in a government deradicalization program, carried out the suicide bombing of a cathedral in the southern Philippines in January that killed more than 20 people.

Indonesia’s National Police spokesman Dedi Prasetyo told a news conference Tuesday that an Islamic militant arrested in East Kalimantan last month had confessed that he’d recruited Rullie Rian Zeke and his wife, Ulfah Handayani Saleh, for the Philippine bombing.

The arrested militant, identified only as Yoga, and the couple he recruited for the bombing were part of Jemaah Anshorut Daulah, a banned Islamic extremist organization in Indonesia that allies itself with the Islamic State group, according to police. Yoga also had contacts with IS militants in Afghanistan.

Prasetyo said Zeke and Saleh had previously failed in an attempt to reach Syria with their children, and after returning to Indonesia underwent a government deradicalization program before being released.

The couple’s alleged role in the bombing of the Roman Catholic cathedral in Jolo highlights links between militants across Southeast Asia. Authorities are concerned about Indonesian, Malaysian and Philippine citizens who joined IS in Syria and Iraq returning home and carrying out attacks in Southeast Asia.

The Indonesians’ involvement in the cathedral attack was initially suspected from the interrogations of five militants caught by authorities in the Philippines after the bombings who described their accents and habits, Prasetyo said.

Some Indonesian militants had tried to reach Afghanistan after the defeat of IS in Syria and Iraq, Prasetyo said, including a man arrested in a Jakarta satellite city who planned a suicide bombing during protests in May against the results of Indonesia’s presidential election.