Dozens of people have been injured in a double bombing, believed to have been set off by Muslim separatists, in front of a supermarket in Thailand.

The blasts happened in the southern city of Pattani in the latest attack in the predominantly Buddhist country.

The latest attack happened at around 2pm local time, with two bombs going off in quick succession outside a supermarket near the city centre.

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At least 40 people were injured in two blasts in the southern Thailand city of Pattani today

The bombs went off outside a supermarket in the southern town at around 2pm local time

Thick smoke was seen coming from the building after the two bombs exploded today

'The first bomb was small and no one was hurt but the second bomb was huge - I don't know yet whether it's a car bomb or not,' Captain Preecha Prachumchai of Pattani provincial police told AFP.

'Currently around 40 people have been wounded: one is in serious condition,' he said.

A decades-old separatist insurgency in the largely ethnic Malay Muslim provinces of Yala, Pattani and Narathiwat has killed more than 6,500 people since 2004, according to independent monitoring group Deep South Watch.

Officials said at least 40 people were injured in the blast, with one left fighting for their life

Investigators at the scene of the attack today, where two car bombs exploded in quick succession, according to police

Last month, the government rejected a conditional offer for peace talks by one of the main insurgent groups, the Barisan Revolusi Nasional, which demanded international mediation or observation.

Pictures posted by rescue workers on Twitter showed a thick plume of black smoke over the supermarket car park and some damage to the store entrance.

Near-daily shootings and bomb attacks have claimed more than 6,800 lives since 2004, with both sides accused of rights abuses and atrocities.

The remains of a car outside the supermarket in Pattani today in the latest of a string of attacks