Indonesia blasts: police concerned about new attack expedients hinh anh 1Indonesian polices guard at May 14 bombing scene (Source: VNA)

Jakarta (VNA)Indonesia’s police are worried about new attacks after a series of bombings hitting East Java province on May 13 and 14 left at least 20 dead and many others injured.

Indonesia’s national police chief Tito Karnavian on May 14 affirmed a family of five, including an eight-year-old girl, conducted the suicide bombing in front of police headquarters in Surabaya city.

The perpetrators of bomb attacks at three Christian churches a day earlier were also identified to be members of a different family, including four children aged 9 to 18.

The use of children in terrorist plots, analysts say, represents a new and shocking development in Indonesia.

Statistics on recent attacks showed that police and religions, excluding Islam, were the targets.

Investigations revealed that bombers used an explosive called triacetone triperoxide (TATP). This type of explosive is commonly used by Islamic State (IS) militants when carrying out terror attacks.

TATP is made from materials that are widely available, Tito told journalists at a press conference in Surabaya on May 14.

Indonesia raised security alert status to the highest level at major cities and regions in Indonesia, including Jakarta capital, Riau islands, East Java and Bali island, after the series of bomb attacks on May 13.-VNA