An army arsenal 260km north-east of Bangkok exploded last Thursday causing a massive fireball and a series of powerful explosions which continued for more than 12 hours.
More than 40,000 residents in a 20km radius were moved to safety. Seventeen people died and more than 90 were injured.
Managing director of Cunningham Lindsey's Bangkok office, Laurence Goodliffe, said: "The scene remained off-limits on Friday due to unexploded munitions scattered over a huge area. Structural damage is significant - unfortunately the buildings and machinery are insured on a fire-only basis and the actual fire damage is not that great."
