"We have caught 16 people for being directly involved in the bombing but one still remains at large," the chief, General Badrodin Haiti, said at the Police Headquarters.
He said the police are now investigating two convicts for their possible involvement in the bombing incident.
So, in all, the total number of alleged perpetrators who were directly involved in the case has reached 19, he said.
General Badrodin said these 19 people were part of five different groups and three of the groups are led by Hendro Fernando, Helmi and Romli. He did not mention the names of the leaders of the other two groups.
"Several groups were involved and they certainly had different plans. This poses a problem that may threaten security," he said.
The bombing on Thamrin Boulevard claimed eight lives, including four bombers and four civilians. The four civilians included a foreigner.(*)