HAT YAI, Thailand (AP) — Police say three boys were killed and their parents were injured in an attack in Thailand’s insurgency-plagued south.

Police Maj. Gen. Pattanawut Angkanawin said Tuesday that gunmen opened fire at the family’s home in the Bacho district of Narathiwat province.

He said the three children, aged 6, 9 and 11, were killed immediately in the Monday night attack.

Pattanawut said the family had returned from a local mosque and was about to enter their house when gunmen shot at them from the roadside.

Police said they were investigating if the deadly assault was carried out by Muslim insurgents, who have targeted Muslims viewed as sympathetic to the authorities.

More than 5,000 people have been killed in Thailand’s Muslim-dominated southern border provinces since an Islamic insurgency erupted in 2004.