A huge explosion occurred at a road checkpoint in Songkhla's Thepha district Tuesday morning, injuring two policemen.

Officials said the explosion was caused by a homemade bomb hidden in an Isuzu pick-up truck without license plate that was seized for checking. 

Pol Cpl Natthapol Chunu and Pol Cpl Apichart Daeng-am were injured in the explosion and were rushed to the Inkayuth Fort Hospital.

The Koh Mor Kaeng checkpoint was manned by troops, police and officials from the Interior Ministry.

The explosion caused a huge fire that burned down the entire checkpoint booth.

The checkpoint is next to Pattani’s Nongchik district and is considered a main gate to the three southern border provinces.