WASHINGTON, Sept 10 — US police officers were combing a dense forest on Monday to locate a man three days after he was suspected of shooting open fire on a highway, injuring five people.

Schools were closed and residents were urged not to be home alone, as police used a helicopter, drones and dogs to aid them in their search in rural Kentucky, in the southeast United States.

Deemed "armed and dangerous,” 32-year-old Joseph Couch is accused of shooting at cars driving along the I-75 highway on Saturday, hitting 12 vehicles and hurting five people, before going on the run.

Officials said Couch — a former US military reservist — had earlier that day legally bought an AR-15 assault rifle and around one thousand rounds of ammunition in the small Kentucky town of London.

"I’m going to kill a lot of people. Well, try at least,” Couch is said to have written in a text message before the incident.

Couch also shared plans to take his own life after the shooting, according to a court document cited by local media.

Authorities have offered a U$5,000 (RM21,650) reward for any information leading to them to Couch.

The search area is challenging, with one official likening it to a "jungle,” and saying: "You actually need machetes and everything to get through these thickets of woods.”

The incident comes after a 14-year-old boy was arrested for allegedly shooting two teachers and two students dead at a high school in Georgia on Wednesday.

Gun violence is common in the United States, a country where there are more firearms than people.

Despite polls showing Americans favour more gun restrictions, a powerful gun rights lobby, constitutional protections and a passionate culture around firearm ownership mean that attempts to clamp down on weapons are always met with stiff political resistance. — AFP