A group claiming to be pro-Islamic State (IS) hackers has threatened to attack the Indonesian government to avenge the “jailing” and “killing” of its “brothers”, a senior counter-terrorism source told Channel News Asia on Thursday. Australia’s consulate in the Indonesian city of Surabaya boosted security measures after a social media post urged militants to “kill” its officials there, Reuters reports. Australia opened the consulate in Surabaya, Indonesia’s second-biggest city, earlier this month. In May, a spate of deadly, ISIS-inspired bombings that rocked Indonesia’s second-largest city, Surabaya, in 24 hours were carried out by three families — including their young children — who targeted churches and the police.