Jakarta, Indonesia ? Indonesian officials interrogated a security guard and another man Tuesday about the deadly nightclub bombing in Bali and said traces of C-4 plastic explosives were found at the scene of the blast.

With Indonesia under increasing international pressure to combat terrorism, a violent Muslim group with ties to Indonesia’s military disbanded the first apparent sign the government was getting serious about moving against Islamic extremism.

The announcement by the group, Laskar Jihad, came as the accused spiritual leader of another extremist network linked to the al-Qaida terror network said he would submit to police questioning.

Most of the nearly 200 victims of Saturday’s blast were foreign tourists, and the grim toll prompted calls for Indonesia to crack down on al-Qaida terrorists and local allies blamed for the bombing. President Bush said Monday he planned to talk to Indonesian President Megawati Sukarnoputri about the need to stop terrorism.

U.S. Ambassador Ralph Boyce met with Megawati on Tuesday to press for action against terrorist groups, a senior Bush administration official said on condition of anonymity. The official could not confirm a New York Times report that Boyce had also warned Megawati the day before the bombing that a group linked to al-Qaida was planning an attacks in Indonesia.

Police spokesman Maj. Gen. Saleh Saaf said police have questioned at least 47 people about the blast and that a security guard and another man were being “intensively interrogated.”

Traces of the military explosive C-4 a putty-like plastic explosive used in the attack two years ago on the USS Cole in Yemen were found at the scene, police said. Richard C. Reid, the alleged al-Qaida-trained shoe bomber thwarted on an American Airlines flight, packed explosive that appeared to be C-4 into his shoes.

In past cases in Indonesia, whenever C-4 has been found in any bombing it has been traced to the military, raising speculation the explosive was bought or stolen from military stocks.

Days after the explosion ripped through the jammed Sari Club, Bali was still struggling to cope with the corpses. At the island’s main hospital now largely used as a morgue dozens of volunteers cared for the bodies, icing them down or loading them into refrigerated containers to slow decomposition in the tropical heat.

Two American deaths have been confirmed: Steven Brooks Webster of Huntington Beach, Calif.; and Deborah Snodgrass, who lived in Bali. U.S. officials said four Americans were injured and up to four were missing. No other names have been released but family members say Jake Young, a former University of Nebraska football player, is missing.