He was admitted to Aek Udon Hospital for emergency treatment.
The attack occurred about 10.30am while he was reading a newspaper at his home near the group's radio station.
He was reportedly hit many times in an arm and leg.
It was not known how many assailants were involved in the attack. Police recovered about 30 spent M16 bullet shells near the fence, which is about 200m from the house.
Mr Kwanchai was last reported to be out of danger.


