The Thai political party whose governments have been overthrown by the country's ruling generals denied on Saturday having any role in the bomb attacks on popular tourist destinations that killed four people and wounded dozens.

The blasts on Thursday and Friday in five of southern Thailand's internationally known resorts came days after Thais voted to accept a military-backed constitution that paves the way for an election at the end of 2017.

Analysts say suspicion would inevitably on fall on enemies of the ruling junta beaten in the referendum or insurgents from Muslim-majority provinces in the south of the mostly Buddhist country.

Fears that followers of former prime ministers Thaksin Shinawatra and his sister Yingluck Shinawatra, including an opposition movement sympathetic to the Shinawatras known as the "red shirts," could be blamed prompted a senior figure in their Puea Thai Party to issue a sharp denial.

"People, through social media, are sending messages saying Thaksin Shinawatra is behind these events," Noppadon Pattama, a former foreign minister, said.

"This is slander and defamation. Anyone who is a former prime minister is worried about the country and would not do such evil," said Noppadon, who served in both Thaksin and Yingluk's cabinets.

No group has claimed responsibility for the wave of bombings, which sent shudders through the tourism industry, one of the few bright spots in Thailand's sluggish economy.

For more than a decade Thailand has been divided between populist political forces led by Thaksin, who was toppled in a 2006 coup, and the royalist and military establishment, which accuses him of corruption.

His sister Yingluk swept to power in an election in 2011, before being ousted in another coup in 2014.

At last Sunday's referendum voters in Thaksin's northeast stronghold voted to reject the constitution, which opponents of the junta said would entrench the military's power and deepen divisions.

Voters in three mostly Muslim southern provinces, where separatists have been fighting with the military for than a decade in an insurgency that has cost 6,500 lives, also voted against the new constitution, while the rest of the country accepted it.

The bombs on Thursday and Friday went off in the upscale resort of Hua Hin and beach destinations in the south including Phuket, Phang Nga and Surat Thani, a city that is the gateway to popular islands in the Gulf of Thailand.

Police and Thailand's foreign ministry initially ruled out links to Islamist terrorism and foreign terror groups, though national police chief Jakthip Chaijinda later told reporters that the devices were similar to those used by Muslim separatists.

Pongsapat Pongcharoen, a deputy national police chief, told reporters on Saturday that no arrests had been made, but DNA samples collected at the blast sites would be compared with DNA samples stored in databases in the southern Muslim provinces.

The attacks came on a busy weekend for tourism as domestic and international visitors flocked to seaside resorts on a long weekend for a public holiday.

Hua Hin, an easy weekend getaway for residents of Bangkok, was returning to normal on Saturday - though most businesses in the vicinity of the Thursday night explosions remained closed, a Reuters witness said.