Security forces are on high alert across the deep South and in key locations in Songkhla after an investigation got under way into a series of coordinated bomb attacks in the region on Sunday night.
In Songkhla's Hat Yai district, checkpoints have been set up and explosive ordnance disposal (EOD) units and equipment to block mobile phone signals deployed at key locations including government offices, shopping centres and markets.
The heightened surveillance and intelligence operations follow two explosions at ATMs in the province on Sunday evening and many more in Pattani, Yala and Narathiwat.
More than 20 incidents were reported, causing at least two injuries. Some turned out to be false alarms and two bombs were defused before they could go off.
In Pattani, authorities reported six explosions at ATMs in four districts wounding two people. In Muang district alone, three bombs went off with one of them wounding two women.
Sompit Sakoljit, 54, and Somjit Srisombat were injured in a blast at an ATM in front of Kasikornbank on Yarang Road in Pattani's Muang district.
One of two bombs planted at an ATM at a hotel was successfully disposed of before it could go off while the other suspicious-looking package turned out to be a false alarm. The other explosions took place in Nong Chik district, Yarang district and Sai Buri district.
Narathiwat officials reported two blasts and a gun attack in two districts.
Bombs targeting ATM machines were reported in Rangae and Bacho districts while gunmen fired shots at a paramilitary ranger base in Bacho district. No one was injured.
According to police, the bombs were found to be of the same type as an explosive device which was found abandoned on Saturday in Sungai Padi district.
Two teenagers reportedly threw it away when they were about to pass a security checkpoint.
In Songkhla, where two explosions were reported, one occurred at an ATM located inside a petrol station in tambon Sakom, Thepha district. The other was at an ATM in tambon Ban Nod, Saba Yoi district. The cash dispensers were damaged but there were no reports of injuries.
Security officials said the two ATM explosions were likely the work of operatives affiliated with the Runda Kumpulan Kecil (RKK) insurgent group.
Led by Bukhoree Kamsoh, the group is known to be active in four districts of Chana, Thepha, Na Thawee, and Saba Yoi.
Authorities also identified the person who allegedly planted the bomb in Saba Yoi district as Wae-koryee Taleh, 28, and they were examining security camera footage to identify the person who planted the bomb at the petrol station in Thepha district.
Police were gathering evidence for submission to Na Thawee court to issue arrest warrants.
In Yala, authorities reported eight explosions including two grenade attacks in four districts of Kabang, Bannang Sata, Than To, and Raman.
There were no reports of any injuries.
In Muang district, authorities defused a 7kg bomb attached to an electricity poll early yesterday as authorities were stepping up security measures.