The discovery of explosive devices in Thailand tourist areas has sparked a warning about the “ongoing” terror risks in one of Australia’s most popular travel destinations.

Security has been tightened at several sites including Phuket International Airport following the alarming finds last week.

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“There’s an ongoing risk of terrorism in Thailand,” a warning from Smartraveller said.

“Popular tourist areas may be the target of terrorist attacks anywhere across Thailand, including Bangkok and Phuket.

“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.”

Local police have made a number of arrests and raided several locations where bomb-making materials were allegedly found, local media report.

The suspects were reportedly from rebel movement Barisan Revolusi Nasional (BRN).

Authorities said the explosive devices were not powerful enough to cause serious injury or kill, and were allegedly part of a plan to spark public panic and disrupt the economy in tourist hotspots.

A number of explosive devices were found last week in Thailand. File image Credit: Tuul & Bruno Morandi/Getty Images

Australian travellers should “exercise a high degree of caution” right throughout the Southeast Asian country, and reconsider travel to Yala, Pattani and Narathiwat provinces in the country’s south because of “low-level insurgent activity, including terrorism”.

“Coordinated attacks have occurred in the southern provinces,” Smartraveller said.

It said the Middle East conflict could also spark attacks against Israeli interests in other regions.

“Be alert to possible threats. Take official warnings seriously and follow the advice of local authorities,” Smartraveller said.

“Border crossing points along the Thailand-Cambodia border continue to be closed at short notice.

“Border areas near Cambodia, Myanmar and Malaysia are dangerous due to violence, armed conflict and landmines. Pay close attention to your personal security.”

Greg Raymond, a Thailand expert from the Australian National University, said the explosives were “certainly concerning” but did not believe the country was necessarily becoming more dangerous.

He was unsure if BRN was involved in planting the devices, saying there were a number of movements in the country.

“There is speculation about who is behind it, and there is precedence for violence in the south to spread to the northern regions, but it’s very rare,” he told 7NEWS.com.au.

Thailand, where more than 800,000 Australians headed every year before the pandemic, is also in the middle of a political storm following a leaked call involving its PM and Cambodia’s ex-leader over a border dispute.