Police investigating Saturday's terrorist bombings on Indonesia's resort island of Bali have questioned dozens of witnesses and widened their search for the masterminds of the attack, which claimed 22 lives, including those of three suspected suicide bombers.
Police say they have questioned 39 people in connection with the near simultaneous blasts that ripped through two popular tourist areas Saturday in Bali, but have made no arrests.
Police believe the bombs were strapped to the waists of three suicide bombers who detonated their explosives in restaurants packed with locals and foreign tourists.
National police spokesman Brigadier General Sunarko Danu Artanto says police have recovered batteries, pieces of cable and detonators from the three crime scenes.
Investigators found three severed heads at the crime scenes and police are circulating pictures, hoping someone can identify the men.
Police are also examining amateur video footage showing a man with a backpack strolling calmly through one of the restaurants moments before one bomb went off.
General Sunarko says security forces have also conducted "sweeps" in several locations on Bali looking for those who masterminded the attack.
Indonesian officials believe the bombs were the work of regional terrorist network Jemaah Islamiyah, the same group blamed for the 2002 bombings in Bali that killed 202 people.
Jemaah Islamiyah is also believed to be responsible for the 2003 bombing of the Marriott Hotel in Jakarta that claimed 12 lives and the 2004 bombing outside the Australian embassy in Jakarta that killed 10 people.
Muslim cleric Abu Bakar Bashir, the alleged spiritual leader of Jemaah Islamiyah, who is currently in jail, condemned the latest attacks in a statement released by his lawyer.
Bashir was sentenced to 30 months for involvement in the criminal conspiracy leading to the 2002 Bali bombings, but was cleared of the more serious charge of planning terrorist attacks.
Security has been stepped up across the region since Saturday's blasts. Australia is warning its citizens of more possible bombings on Bali.
Thailand, which is battling a Muslim separatist insurgency in the south, has tightened security in tourist areas and at strategic sites such as embassies and airports.