Thailand's restive southern provinces were rocked by a wave of coordinated bomb blasts and arson yesterday, a day after the country enacted a new Constitution.

The 23 incidents, including arson and five small bomb attacks, caused widespread blackouts in four southern provinces but no casualties were reported.

Analysts said the attacks were likely meant to undermine the military. But they were divided on whether these were directly connected with the signing of a new charter that was overwhelmingly rejected by the three border provinces of Pattani, Yala and Narathiwat during the ratification last August. Several attacks also occurred in the southern province of Songkhla.

The new Constitution will curb the power of lawmakers but boost the army's role in government, even after the junta led by Prime Minister Prayut Chan-o-cha steps down after expected polls late next year.

"The whole idea is to humiliate the Thai security apparatus. Right now, their aim is to make the area ungovernable as much as possible," Mr Don Pathan, an analyst who writes on southern Thailand issues, told The Straits Times.

This year alone has seen six violent incidents in the south killing 13 people, all happening last month.

"The incidents are to create disturbances. They want to destroy the government's credibility and create fear among people," said Mr Pramote Prom-in, a spokesman for local security forces.

The southern provinces have been rocked by violence for more than a decade as Malay Muslim rebels battle Thai troops for more autonomy from the Buddhist-majority state.

The fighting has claimed more than 6,500 lives since it escalated in 2004, according to independent monitoring group Deep South Watch.

There is a possibility of more violence erupting with rebels asserting their independence against Bangkok, said Mr Kan Yuenyong, executive director of the Siam Intelligence Unit.

But such moves will likely be contained by the military, which has become more powerful under the new Constitution signed by King Maha Vajiralongkorn on Thursday.

"This may be related to the idea of Bangkok centralisation and governance. Overall, it's seen as trying to create resistance to Bangkok and test reactions on the ground. It's about ideology, psyche," Mr Kan said. He likened the situation in the south to simmering water that may spill over as the government has so far failed to make headway in negotiating with the rebels.

The government struck a deal in February with Mara Patani, an umbrella group that claims to speak for the insurgents. But the deal was rejected by other separatists.

Thailand's ethnic and religious separatist insurgency originated in 1948 in the Malay Pattani region that borders northern Malaysia.

The separatist movement became increasingly violent from 2001 as local leaders demanded a level of autonomy from Thailand for the Pattani region. The Barisan Revolusi Nasional, a leading group in the insurgency, has been involved in suspected killings, arson and bomb attacks.

Said Mr Kan: "We are all aware of the junta's propaganda to the public that their governance has been able to maintain peace and security. But if you look at the reality, that's not true at all."