Three people were shot dead after a gunman opened fire at a radio station in Thailand this morning (May 27).

The alleged shooter Win Sonsuk had worked as a mechanic at the building operated by the National Broadcasting Services of Thailand in Phitsanulok province, around 250 miles north of Bangkok.

He allegedly opened fire shortly before 10am local time. One of the dead men was slumped behind radio equipment in one of the studios and another had staggered out onto the lawn in front of the building. Another was found dead in a corridor.

Win Sonsuk, wearing a purple shirt, was pictured in handcuffs and covered in blood as police lead him in handcuffs out of the building.

The alleged victims were radio station director Sanit Butmongkol and electricians Jirawut Sumethepanan and Bhumisaran Panbhumi.

Officers said they were able to subdue the alleged gunman. They said that two hand guns, several bullets, a pocket knife and a smartphone had been found on him.

Lieutenant General Apichart Sirisith said the alleged killer had planned the shooting in advance.

The police chief said the station director had tried to run away but was chased down and killed at the back of the building. He was the last person to be shot.

Investigators were still questioning witnesses and collecting evidence from the scene. The shooter's motive was not yet known.

Police said the suspect was in custody and being monitored closely.