Kowit's signature, which is the final step in indicting the senior military officers, came after a onehour meeting with several senior police officers including chief investigator of the case, Central Investigation Bureau head Pol Lt General Montree Jamroon.

The four suspects are Maj General Phairoj Theerapharb, Colonel Suraphol Supradit, Lt Colonel Manas Sukprasert and Lieutenant Thawatchai Klinchana, all of whom are attached to the Internal Security Operations Command (ISOC).

The officers all face six charges: criminal conspiracy to commit premeditated murder; attempting to kill a state official on duty; possessing explosives; having nonauthorised items in their possession; forging and using official documents; and criminal conspiracy.

SgtMajor Chakhrit Janthara, an ISOC officer whom police say was responsible for obtaining a Daewoo sedan that was found carrying a large amount of explosives and a blasting agent, would not be charged in exchange for turning state's evidence against the four officers.

Phairoj, the only suspect not in military custody, is required to report to a military prosecutor soon.

The investigation report for the case is over 3,000 pages long and includes interviews with 106 witnesses.

The Nation