Thai police on Wednesday surrounded a house where a gunman had holed up after killing two people and wounding another, a spokesman said.
The shooter started firing in Phetchaburi -- some 100 kilometres (60 miles) southwest of Bangkok -- at around 3 pm (0800 GMT), national police spokesperson Achayon Kraithong told AFP.
"Police are still surrounding the area... where a man with a gun started shooting and killed two men and wounded one," he said.
"The incident is still going on," he added, declining to give further details.
Thailand has high rates of gun ownership and there has been a steady trickle of violent incidents in the past 12 months, including one of the deadliest attacks in recent history.
The kingdom was left reeling in October after a former police sergeant murdered 36 people, 24 of them children, in northeastern Nong Bua Lam Phu province.