The injured guard was identified as Samran Chanthong-on, 36, a resident from Cha-uat district of Nakhon Si Thammarat.
He was shot on the left shoulder by shotgun bullets.
According to the Thung Songhong police, a man riding in a motorcycle came near the road blockade and was seen to have a talk with the guard. Shortly after a talk, the man left in his motorcycle and a gunshot was fired into a group of guards.
Samran fell on the ground after being hit by a bullet.
He was rushed to Mongkutwattana hospital for treatment. Doctors said he is now safe but still has to remain in hospital to recover from shot wound.
Police suspected the man might be angry when he could not pass the blockade and shot at him.
Police said they are looking into video footages from several surveillance cameras on the road to bring the gunman for trial.
THAI PBS ##########
The shooting occurred at about 02.30 a.m. today at a coffee house “A Big Seat” which is in front of the office of the Democrat party. A group of protesters from Rayong province was camping out near the coffee house. They arrived in Bangkok to join the Bangkok Shutdown protest today.
A Camry sedan was reported to come near the office and a man was seen sliding down the side windshield and sprayed bullets into the coffee house.
The driver then sped off immediately.
There was no injury but the glass door and window of the coffee house were broken with a dozen of bullets.
Forensic police arrived to inspect the scene this morning to collect evidence.
Police said it might be the work of ill-intention people wanting to incite violence.
The shooting was reported to Muang Udon police station this morning by Sub Lt Arunee Yothavichit, a land official at Phen district.
She said she was inside the house when she heard sound of gunshots at about 02.00 a.m. today. At first she thought the sound was from firecrackers and did not come out to see.
However, when her husband returned home and alerted her that her car parked inside the house was riddled with several bullets. She then came to see and found that her Honda car was riddled with four bullets.