The moment a bomb exploded outside a busy shopping centre in Thailand has been caught on video.

Shoppers had already been evacuated from the Big C mall in Pattani after attackers set off firecrackers inside.

Pramote Prom-in, a spokesperson for the Thai military, said they were believed to be a distraction ahead of a car bomb detonated outside the entrance.

Thai soldiers stand guard as a forensics unit inspects the aftermath of a car bomb in front of Big C in the town centre of Pattani on 9 May (AFP/Getty Images)

Footage showed a huge fireball explode as shoppers held back by police turned and ran for their lives, with the sound of children crying heard in the panic.

No deaths were immediately reported but Pattani Hospital said at least 52 injured people were being treated, with two in a critical condition.

The attack was blamed on separatist groups who have been waging a bloody insurgency in southern Thailand for more than a decade.

Islamist militias linked to al-Qaeda are among those fighting and launching terror attacks in three Muslim-majority provinces, where more than 6,500 people have been killed since 2004.

Rewat Srichantub, Pattani's deputy police chief, blamed Islamist insurgents for the latest attack and said the bomber was believed to have fled the scene before the blast.

Attacks in mainly Buddhist Thailand's southernmost provinces, near the border with Malaysia, have intensified this year, with six army rangers killed in an attack last month.

Pattani has repeatedly been hit by waves of violence, including twin bombings in August.

In pictures: Thailand bombings Show all 7 1 /7 In pictures: Thailand bombings In pictures: Thailand bombings An injured person is helped after a bomb blast in the southern resort city of Hua Hin on 11 August AP In pictures: Thailand bombings An injured person lying on the ground after a bomb blast in Hua Hin, Thailand, 11 August 2016. EPA In pictures: Thailand bombings An injured man being helped after twin bombs exploded in the resort of Hua Hin, Thailand, on 11 August AFP/Getty Images In pictures: Thailand bombings Thai rescue workers rush an injured bomb victim to a hospital following a bomb attack at the city clock tower in the center of Hua Hin, Thailand, 12 August 2016. A EPA In pictures: Thailand bombings Injured people receive first aid after a bomb exploded on August 11, 2016 in Trang, Thailand. Reuters In pictures: Thailand bombings A damaged street food vendor stall is seen where a small bomb exploded in Hua Hin on August 12, 2016. AFP/Getty Images In pictures: Thailand bombings An injured man receives first aid after two bombs exploded in the Thai seaside resort of Hua Hin on 12 August Reuters

Prawit Wongsuwan, the defence ministry in Thailand’s military junta, claimed that attack was not related to a string of attacks on tourist hotspots including Hua Hin and Phuket.

The government, which came into power in a 2014 coup, recently rejected a conditional offer for peace talks from one of the main insurgent groups, the Barisan Revolusi Nasional, which had demanded international mediation or observation.

Martial law has been imposed in the provinces of Pattani, Yala, Narathiwat and parts of Songkhla since 2006, allowing security forces to detain suspects without charge, censor the media, conduct searches and seize documents.

The Foreign and Commonwealth Office advises against “all but essential travel” to the region, while warning that further terror attacks are “very likely” in Thailand.

“Bomb and grenade attacks have been indiscriminate, including in places visited by foreigners,” its advice states.

“Since 2004, there have been almost daily attacks in the far south of the country, including arson, bombings and shootings.

“Targets have included civilians and members of the security forces, government offices, tourist hotels, discos, bars, shops, marketplaces, supermarkets, schools, transport infrastructure and trains.”

