National Police spokesman Boy Rafli Amar said the men were arrested in several locations on the island of Java yesterday and were connected to four militants ambushed by police on the same day near Jakarta. One of those in the ambush was fatally shot by police.
Amar said all eight were members of Jemaah Anshorut Daulah, a network of Indonesian extremist groups led by imprisoned radical cleric Aman Abdurrahman that was formed in 2015 and pledges allegiance to Islamic State group leader Abu Bakr al-Baghdadi.
Suryadi Mas'ud, one of the suspects arrested yesterday, told police his role was to purchase rifles from militants in the Philippines and he had traveled there several times to meet Isnilon Hapilon, an Abu Sayyaf commander, who agreed to provide M16 and M14 rifles.
Amar said the group was planning to establish a new jihadist training camp after IS-affiliated militants based in Poso on Sulawesi were decimated by a months-long police and military campaign that also killed their leader, Abu Wardah Santoso.
Amar said earlier investigations found that five guns had been sent from the Philippines to Indonesian militants. Two of them were used in a Jakarta suicide bombing and gun attack in January last year that killed eight people including four attackers, he said.