Indonesian police said they had found two separate collections of bombs as they imposed a major alert following foreign warnings of an impending terrorist strike.
The discovery came as police were being deployed across Indonesia in a huge security operation after Australia said terrorists may be plotting to strike in the run up to Christmas, specifically naming the Hilton hotel chain.
Britain and the United States have also warned that their citizens in Indonesia over Christmas and the New Year faced a “heightened risk” of attack.
New Zealand has cautioned against non-essential travel to the country.
National police chief Da’i Bachtiar told reporters that nine tubes of explosives were found on a bus in West Java, a heavily-populated area thought to be a major recruiting ground for Islamic extremists.