A man who was seriously injured on Tuesday when potassium chlorate, stored in a house at a longan orchard in Chiang Mai province, exploded, succumbed to his injuries, bringing the death toll to three.

An earlier report stated that two women were killed from the impact of the blast.

Warut Visitsilp, the district chief officer of Phrao district, who inspected the scene of the explosion, said that the potassium chlorate was used to force the flowering of the longan trees in the orchard.

He added that forensic investigators will inspect the house again today, to trace the cause of the explosion and to determine whether the potassium chlorate, which is also used in the manufacture of some ammunition and pyrotechnics, was being stored properly.