The Department of Foreign Affairs and Trade warns the "security situation in Thailand can be unpredictable".(ABC News: Mazoe Ford)
Thai authorities allege Malay-Muslim militants planted improvised explosives at 11 sites in popular tourist destinations Phuket and Krabi.
In response, Australia's Department of Foreign Affairs and Trade issued a warning about the "ongoing risk of terrorism" across Thailand.
Insurgents have routinely targeted civilians in Thailand's southernmost provinces, but one expert told the ABC they were not known for striking areas such as Phuket.
The Australian government has warned travellers of an "ongoing risk of terrorism" across Thailand after police reported finding improvised explosives in tourist areas around Phuket and Krabi.
"Popular tourist areas may be the target of terrorist attacks anywhere across Thailand, including Bangkok and Phuket," said a statement posted to the Department of Foreign Affairs and Trade's Smartraveller website.
"Phuket International Airport has increased security measures and passengers should arrive early for their flight. This follows the recent discovery of an explosive device near the airport.
"Thai authorities also defused devices in Phuket, Krabi and Phang Nga and made arrests."
Thai officials said on Friday they had arrested two suspects allegedly connected to the Barisan Revolusi Nasional (BRN), the leading group in adecades-long separatist movementwhich seeks independence for Thailand's southernmost provinces which are majority ethnic Malay and Muslim.
In comments carried by Thai PBS, a spokesperson for the Thai military said two men in their 20s were alleged to have planted some 11 improvised explosive devices in Phuket, Krabi and Phang Nga.
Australia has also advised caution around political demonstrations in Thailand.(AFP: Lillian Suwanrumpha)
Army commander Lieutenant General Paisal Nusang said the devices were not powerful enough to cause serious damage or kill, but rather appeared intended to disrupt economic activity in tourist-heavy areas.
Phuket Governor Sophon Suwannarat last week sought to downplay the threat to tourists in his province.
"Based on current evidence, none of the suspicious items found so far are explosive or destructive," he said as quoted by the Bangkok Post.
BRN's attacks have historically been focused in Thailand's deep southern provinces of Pattani, Yala and Narthiwat — not tourist areas further north like Phuket.
Greg Raymond, an expert on Thailand at the Australian National University Strategic and Defence Studies Centre, was sceptical that BRN would be behind an explosives plot so far north.
"There hasn't been any real evidence of movement of the insurgency outside the three border provinces for quite some years," he said.
"This looks like perhaps a couple of amateurs [who] don't seem to have the skills that the Barisan Revolusi Nasional, the main insurgency group, have down in those three border provinces."
Deep South Watch, a non-profit organisation which monitors the conflict in Thailand's south, says more than 7,700 people have died as a result since 2004.
DFAT has long warned against travel to the southern three provinces, which border Malaysia, "due to ongoing risks of low-level insurgent activity, including terrorism".
The alleged bomb plot against tourism sites in Phuket and Krabi comes after BRN in May publicly disavowed violence against civilian targets.
"We insist that we will conduct our activities under the framework of international human rights principles and laws," the militant group said a statement in Malay translated by Thai PBS.
Malay-Muslim insurgents have long attacked civilian targets in Thailand's southernmost provinces, such as this attack on a convenience store in 2022.(Reuters: Surapan Boonthanom/File)
Human Rights Watch's Asia director Elaine Pearson said the public pledge not to target civilians was an "unprecedented step … after terrorising people in Thailand's deep south for more than two decades".
Deep South Watch reports at least 245 people have been injured in violent incidents involving insurgents this year.
Thai Police did not respond to ABC questions on the nature of the devices or the ongoing risk posed to tourists.
Pravit Rojanaphruk, a prominent Thai journalist with Khaosod English, said little was known about the devices or the suspects.
"Since the case has yet to be brought up before a court of law, all we have at the moment is what the police said was a confession," he told the ABC.
The second-largest party in Thailand's ruling coalition has spectacularly pulled out, leaving the country's embattled prime minister with a slim majority.
In its travel warning, DFAT added that the "security situation in Thailand can be unpredictable".
"Large protests have occurred in Bangkok and other areas," they said.
"In previous years, large political protests and government crowd control operations have resulted in violence."
Thousands of protesters last weekend gathered in Bangkok to call for the resignation of Prime Minister Paetongtarn Shinawatra, whose government is at risk of collapse over a border dispute with Cambodia.
Rojanaphruk said Australians who were worried could postpone their trip to Phuket by a week or two "just to see how things pan out."
"I do not think that it's as dangerous as some countries in South-East Asia, but it's good to be vigilant," he said.
"I would be more concerned about swimming on the beach and being sucked down by a rip curl, which has actually killed a few people over the past month or two in Phuket alone."
Topic:Disaster and Emergency Response