At least 20 ATM booths at multiple locations in violence-plagued southern Thailand were bombed early Wednesday morning.

The ATM booths were reportedly bombed near-simultaneously across restive southern Yala, Pattani and Narathiwat and Songkhla provinces, Xinhua reported.

Initial investigations found that the explosive devices were triggered by using mobile phones.

CCTVs in Yala's Yaha district caught the images of two suspects, a man and a woman, on a motorcycle.

National Security Council (NSC) chief Paradorn Pattanatabut Wednesday said he believed the ATM bombs were aimed at marking the anniversaries of the founding of several insurgent groups.

The Barisan Revolusi Nasional (BRN), the major insurgent group in the deep southern Thailand, was founded Oct 10, he added.

More than 5,000 people have been killed and more than 9,000 injured in over 11,000 incidents of separatist violence since January 2004 in Thailand's Muslim, ethnic-Malay-dominated southern region, according to Deep South Watch, which monitors regional violence.

The region comprises the three border provinces of Yala, Pattani, and Narathiwat and four districts of Songkhla.