Police believe the death is not part of the unrest that has plagued the country’s deep South for over a decade.
“The killers may want to disguise their crime as a security case,” a police source said.
The shooting was reported to Rueso police about 10pm on Thursday.
The 47-year-old victim's name is being withheld because of the possible motive behind the murder. He sustained three gunshot wounds to the head, chest and right arm.
“I was tapping rubber when I noticed three men suddenly run out of a rubber forest on the other side and opened fire on an oncoming sedan,” a witness said on condition of anonymity.
The witness said after a few gunshots, the car lost control and swerved into the roadside.
“One of the gunmen then opened the door of the car and fired one more shot as if to make sure that the victim would be dead,” the witness said.
Fearing for his own life, the witness said he turned on his lamp.
“After the shooting, a pickup came to the scene and took all three gunmen,” the witness added.
Police came to the scene on Friday morning to gather evidence.