PHOTO: The Jakarta Post/Asia News Network
National Police chief Gen. Tito Karnavian has said the terrorists behind a series of suicide bomb attacks at three churches in Surabaya, East Java, on Sunday, used an explosive type called triacetone triperoxide (TATP). This type of explosive is commonly used by Islamic State (IS) militants when carrying out terror attacks.
TATP, sometimes referred to as "Mother of Satan", is made from materials that are widely available on the market, Tito said.
"All of those materials are very dangerous since they can easily trigger an explosion at random because of their sensitivity," he told journalists in a press conference Surabaya on Monday.
Tito added that unlike any other explosives, TATP did not need a detonator to set the bomb off. "Heat or a mere shaking motion can cause the bomb to explode."
13 dead, 40 injured in Indonesia church attacks
Although TATP is made from widely available materials, Tito explained, the explosive could create a bigger explosion than TNT. It is also difficult to detect it by X-ray, making it a popular type of explosives among terrorists.
Several major bombing incidents causing multiple fatalities, such as the 2005 London bombings, the 2015 Paris bombing, the 2016 Brussels airport bombing, as well as last year's bombing of the Manchester Arena, used TATP.
Before Sunday's Surabaya church bombings, this type of explosive was first reportedly used by Leopard Wisnu Kumala, a 29-year-old man who attempted to extort money from Alam Sutra Mall management by threatening to explode several bombs in the mall in October 2015.