BANGKOK, July 26 — Senior Thai police officers Monday said they believed a bomb which exploded at a busy bus stop outside Big C department store in the capital was an M67 type and the bomber must have been expert in using it.

Pol Gen Panupong Singhara Na Ayutthaya, national police chief adviser, told journalists after chairing an urgent police meeting on Sunday’s bombing incident that police initially believed the explosive was an M67 type.

He said the bomber used a fuse attached to the device and set the time with an alarm clock. The builder must have been expert as the circuit had to be changed and the fuse had to be removed before the bomb could explode.

After watching a closed-circuit television monitor installed near the scene of the incident, police saw a suspected bomber in the picture but they are still uncertain, said Gen Panupong.

MCOT