Hxen.com's tips：Every day persisted can learn English well!-->■Learn English Everyday■
The explosives found in suicide bombings shared some similarities with those found in a raid in Cilacap district of Central Java days ago, he said.
"In a raid in Cilacap district, the bombs found was identical with the bombs here," he told reporters at the scene.
The police on Sunday arrested a terrorist suspect in the district and confiscated explosive materials.
The police chief also said that the undetonated bomb found at the 18th floor at JW Marriott hotel also had similarity with materials of the bombs at the blast scene.
In addition, the police also found two heads of the allegedly suicide bombers at the scene.
Hendarso said that the two heads found were expected to help police investigate the case.
A cctv recording has also displayed the sequences of bombings, as a man carrying a bag seconds before the explosion.
In 2003, a suicide bombing hit JW Marriott hotel, killing 12 people and wounding over 100 others.