Pressure cooker bombs caused the explosions that blasted the Kampung Melayu bus terminal in East Jakarta on Wednesday evening, a police official has said.
National Police spokesman Insp. Gen. Setyo Wasisto said on Thursday that the perpetrators filled pressure cookers with explosive materials, nails and buckshots.
"Based on the crime scene investigation, two of the perpetrators carried the pressure cooker bombs in their carrier bags. We found [pieces of] nails and buckshots in the pressure cooker" he said as quoted by kompas.com.
Setyo added that the police also found a store bill indicating a recent purchase of cooking pans in a pocket of one of the suspected suicide bombers.
"The bill of the cooking pan purchase on May 22 was found in the pocket of one of the alleged perpetrators," he said as quoted by tempo.com.
Two explosions blasted a Transjakarta bus terminal in East Jakarta at around 9 p.m., killing three police officers and injuring ten others.
Acts of terrorism involving pressure cookers are common in Indonesia.
Last December, National Police counterterrorism squad Densus 88 confiscated a pressure cooker containing triacetone triperoxide (TATP) from terrorists in Bekasi, West Java. The terrorists allegedly planned to attack the State Palace in Central Jakarta.