Hua Hin - Thai authorities on Saturday hunted for culprits behind a wave of bombings targeting popular holiday destinations, as businesses braced for the economic fallout from the attacks on the crucial tourism industry.The kingdom was on edge after 11 small bombs and a series of suspected arson attacks exploded across five southern provinces on Thursday night and Friday morning, killing four locals and wounding more than 30 people - including foreign tourists.The bombs, most of them detonated in twin blasts, struck key tourism hubs during a long weekend, including the seaside resort town of Hua Hin and the island of Phuket.No one has claimed responsibility for the attacks, but police have ruled out international terrorism and said the campaign was an act of "local sabotage".They said the motive was still unclear, but stressed the assault was not connected to a simmering insurgency in Thailand's southern tip, as some analysts have suggested."I can assure you that this is not a terrorist attack or the expansion of militants from the three southernmost provinces," deputy police commissioner Ponsapat Pongcharoen told reporters.If the southern Muslim rebels are to blame, it would mark a major expansion of a secessionist campaign that rarely targets foreigners. It would also be a huge embarrassment to Thailand's coup-installed military government, which has made boosting national security a flagship policy of its regime.Senior junta member and defence minister Prawit Wongsuwan told AFP an arrest warrant would be issued later Saturday but offered no details.'Confidence will return'In hardest-hit Hua Hin, a popular beach resort far from the conflict zone that was rocked by four bombs, locals said they were fearful the town's mainstay tourist industry would suffer just ahead of peak season."Hua Hin has never had a problem like this," Nai Amporn, the owner of a beachside restaurant, told AFP."I am afraid business will become slow - even this morning, you can see there are fewer people here for breakfast. I think they have all gone home," he added. Famed for its idyllic islands and Buddhist temples, Thailand is a tourism powerhouse and was hoping for a record 32 million visitors this year.The sector accounts for at least 10% of Thailand's economy, which the military government has struggled to invigorate since its 2014 power grab."The confidence in tourism will return," Tourism Minister Kobkarn Wattanavrangkul said Saturday, adding that the industry is still aiming to reach a target revenue of of 2.4 trillion baht for 2016."Thailand solves problems very quickly and always bounces back," she said.Thailand's reputation as a holiday-maker's paradise has weathered fatal bus and boat accidents, bouts of political unrest and high-profile crimes against foreigners in recent years. But the tourists keep coming.An August 2015 bombing at a Bangkok shrine that killed 20 people - mostly tourists - was followed by a sudden drop in visitors but did not stop the kingdom from welcoming a record high of nearly 30 million travellers that year.'Rebels capable'The recent bombings were aimed at striking the vital tourism sector without causing extensive carnage, said Anthony Davis, a security analyst at IHS Jane's."This will have a significant impact on the tourist season in the south this year and into early 2017, using tactics that were clearly intended not to cause mass casualties," he told AFP.He said southern insurgents were the only group capable of carrying out the coordinated assault, dismissing theories that the junta's other political foes - who have been under close surveillance since the 2014 coup - were responsible."They have the operational infrastructure and the manpower - arguably, extending the campaign in a striking manner was only a matter of time," he told AFP, adding that the junta's attempts at peace talks with the rebels have faltered.The bombings came less than a week after the military regime's draft of a new charter was approved in a referendum. The poll was held in in a repressive climate, with criticism of the draft banned under a draconian anti-campaigning law. Provinces in the rural north and northeast - strongholds of the ousted government - rejected the junta's charter. So did the three southern insurgency-wracked provinces, which saw an uptick in bombings in the run-up to the vote.The southern rebellion, waged by Muslim militants seeking greater autonomy from the Buddhist-majority state, has killed more than 6,500 people since it erupted in 2004.