The most prominent insurgent group in Thailand's south rejected the military's peace plan in a rare statement on Monday, underscoring Bangkok's inability to open negotiations with the actual fighters in the conflict.
The country's southernmost border provinces, which were annexed by Thailand more than a century ago, have been plagued with violence for over a decade as ethnic Malay rebels battle Thai troops for more autonomy from the Buddhist-majority state.
The fighting has claimed more than 6,800 lives -- mostly civilians -- since 2004, with both sides accused of rights abuses and atrocities.
The shadowy Barisan Revolusi Nasional (BRN) is believed to be behind much of the violence, although it never claims attacks and shuns publicity.
On Monday it outlined objections to Bangkok's peace plan, saying it "must include the participation of third parties (international community) as witnesses and observers" and that an "impartial" mediator should lead the talks, not the Thai army.
In February the military and a group of rebel peace negotiators agreed to create a cluster of "safety zones" -- the first small but significant step in a much delayed peace process.
Thailand's generals, who seized power in 2014, touted the deal as proof the army-led peace process had legs.
But many experts have long remarked that the only rebel group Bangkok will agree to talk to -- the Mara Patani -- has little control over fighters on the ground.
Thailand's military treats the insurgency as a purely internal security issue and has baulked at any suggestion of outside involvement from the international community.
There have been talks in the Malaysian capital Kuala Lumpur with Mara Patani. But they have staggered on for years, undercut by near-daily bombs, ambushes and assassinations in the Deep South and a decade of political instability in Bangkok.
Matthew Wheeler, an expert on the southern insurgency with the International Crisis Group, said the BRN "perceive the current (peace) process as one driven by Bangkok and Kuala Lumpur for their own interests".
But he added that statement reminds both sides the BRN is willing to come to the table under the right conditions.
"It does not reject dialogue, even as it rejects participation in the current dialogue process," he told AFP.
Monday's statement followed a weekend of coordinated bombings across the south that targeted electricity poles.
The attacks caused widespread blackouts but no casualties and were seen as a reminder from the insurgents that they can still cause trouble despite a strong military presence and harsh martial law restrictions.
Those bombings came hours after Thailand's new King Maha Vajiralongkorn signed into law a military-backed constitution that will curb the power of elected lawmakers and bolster the army's role in any future government.
The southern region was one of few areas to reject that constitution when it was put to a referendum last year.