Two suspects in a spate of bomb attacks on Thailand’s tourist towns have links to southern Muslim rebels, police said on Monday, the first time a clear link has been made to the insurgency.

No one has claimed responsibility for the bombing and arson spree which hit popular resorts across the south this month, killing four and wounding dozens including European visitors.[restrict]

But the attacks have heightened concerns the ethnic Malay insurgency may have spread north after years of stalled peace talks — a theory the country’s junta has played down given the importance of tourism to the economy.

Three arrest warrants have now been issued by a military court — all for Muslim men from the south.

Usmeen Katemmadee, a 29-year-old from Pattani province named in the latest warrant issued on Monday, is wanted for bomb possession and arson over an attack against Hua Hin, where a double blast killed two people.

Two earlier warrants were for a man called Ahama Lengha from Narathiwat province and for a man named Russalan Baima from neighbouring Songkhla.

Colonel Krissana Pattanacharoen, deputy national police spokesman, said both Ahama and Usmeen had previous links to the southern insurgency.

“The first suspect (Ahama) is directly linked with the insurgency by DNA while the third suspect (Usmeen) has had arrest warrants previously issued for the possession of firearms, explosives and some other charges,” he told AFP.

He said it was not yet clear if Russalan was linked to the revolt.

More than 6,500 people, mostly civilians, have been killed in 12 years of violence between the Buddhist-majority state and the shadowy rebels seeking greater autonomy in Thailand’s three southernmost provinces.

Until now the violence has remained almost entirely local, with the militants wary of attacking foreigners for fear of sparking an international backlash.

Analysts say the junta leadership in its turn fears any admission that southern insurgents were behind the latest attacks might harm tourism, and raise questions about the military’s ability to ensure security.

Yet in recent days the police investigation has increasingly pointed towards the deep south.

– Roadside bombs –

Thailand annexed the culturally and linguistically distinct zone bordering Malaysia over a century ago.

Resistance to Thai rule has existed for decades, but a full blown insurgency kicked off in 2004 and drive-by shootings and roadside bombs are now a near-daily occurrence.

A large car bomb killed two outside a hotel in Pattani on Tuesday.

The rebels never claim their attacks but factions are known to be frustrated with the lack of progress in achieving their goals.

Rights groups accuse soldiers of widespread abuses, including torturing detainees and extra-judicial killings. The rebels also employ brutal tactics, including beheading monks and teachers.

Violence in the deep south has lessened since generals seized power in a May 2014 coup.

But there has been a noticeable uptick in attacks more recently, particularly around the time of a referendum earlier this month on a new constitution penned by the junta.

The charter was approved by a majority of voters but rejected in the three insurgency-racked provinces.

Speaking to reporters on Monday, former army chief turned Prime Minister Prayut Chan-O-Cha said meetings between the government and rebel intermediaries have taken place in Malaysia but insurgents must halt their attacks.[/restrict