Attacks were reported in Pattani, Yala, and Narathiwat provinces, according to the reports, which also said gunfire was heard in at least one area.
Southern region military spokesman Colonel Piamote Prom-In told Thai television the attacks broke out in several places this evening.
"The explosions occurred in busy areas as people were shopping ahead of curfew," he said, referring to a night-time curfew imposed since Thursday, when the kingdom's army chief seized power in Thailand, deposing the civilian government.
The Bangkok Post said at least 13 attacks erupted in Pattani provice at about the same time, suggesting a coordinated offensive, at "three 7-Eleven outlets, the office of the Provincial Electricity Authority (PEA), an electricity facility and a petrol station in Muang district."
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The district was left without electricity after the attacks, it said, adding that police reported gunfire was heard near the PEA office.
No further details were immediately available on the victims or who was behind the attacks.
But suspicion was likely to fall on Islamic insurgents in the Muslim-majority region, which borders on predominantly Muslim Malaysia.
But for the most part, it has been civilians caught in the cross-fire of the regular bombings, shootings and sometimes beheadings.
The conflict has claimed more than 6,000 lives, mostly civilians.
Thailand annexed the deep south more than a century ago.
The rebels want a level of autonomy, accusing Thai authorities of riding roughshod over their Malay culture and carrying out human rights abuses.
Observers say there has been an uptick in the violence in recent months following the suspension of peace talks between some rebel factions and Thai authorities.