Police suspect Muslim separatists were behind six killings in Thailand's far south that have come as the country celebrates its traditional New Year.

Two farmers were shot dead on their rubber plantation in Yala province on Monday, while four people in two neighboring houses were fatally shot Sunday night in Narathiwat province.

More than 5,000 people have been killed in Narathiwat, Yala and Pattani provinces since an Islamic separatist insurgency erupted in 2004.

Police are still investigating the latest attacks, but believe they were carried out by Muslim insurgents because intelligence indicated that there would be attacks on Buddhists during the New Year festival, known as Songkran.

Thailand's three southernmost provinces are the only ones with Muslim majorities in the predominantly Buddhist country.