The Islamic State militant group has a presence in nearly all provinces across Indonesia, the world's largest Muslim-majority country, the military chief has said. <br/><br/>General Gatot Nurmantyo said the clandestine sleeper cells across the sprawling Indonesian archipelago underscored concerns about Islamic State's growing influence in Southeast Asia. <br/><br/>He told reporters in Jakarta that these sleeper cells can easily join up with other radical cells. <br/><br/>He said governments across the region have been on high alert since Islamic State-linked militants, mostly from Southeast Asian countries, overran a city in the southern Philippines about three weeks ago.