Indonesian anti-terrorism police have detained three former students in a raid on a university campus in Pekanbaru, on Sumatra Island, and seized crude bombs and other explosive material, police said. The men are thought to have been planning to attack the local parliament in Pekanbaru, the capital of Riau province. Authorities have highlighted concerns about a rise in radicalism at universities in the world’s biggest Muslim-majority country. A number of recent surveys of students have pointed to significant support for Islamic State, carrying out jihad and the establishment of a caliphate in Indonesia. Last month, police shot dead four men who used samurai swords to attack officers at police headquarters in Pekanbaru.