BANGKOK, June 19 (Xinhua) -- Five Thai soldiers were killed and four others injured in a blast at about 11:45 a.m. local time Monday in Thailand's southern Pattani Province.

Thai media Matichon said the number and identity of the attackers remain unknown.

Pattani, along with Yala and Narathiwat, are the three southernmost provinces of Thailand that were haunted by explosions and attacks.