jakarta indonesian anti-terrorism police detain 18 people link militant group bid cut risk attack christmas new year world big muslim-majority country police say monday near-simultaneous attack church capital jakarta elsewhere christmas eve 2000 kill nearly 20 people ever since authorities step security church tourist spot holiday police chief tito karnavian say evidence specific plot detentions make bid head trouble pre-emptive strike karnavian tell reporters majority link previous incidents people arrest early say police say 12 people detain south sumatra four west kalimantan one malang east java one surabaya province indonesia anti-terrorism laws investigators hold people seven days determine whether designate suspect release say police spokesman setyo wasisto indonesia see share militant attack years aim foreign christian government target include blast tourist island bali 2002 kill 202 people since police manage stamp weaken many militant network although resurgence radicalism recent years inspire largely islamic state series small-scale attack since early 2016 link islamic state believe thousands sympathizers indonesia indonesia detain 18 pre-emptive bid boost christmas security