Four soldiers were injured when a bomb exploded at a sports event in conflict-ridden southern Thailand.

The state defence volunteers were handling security when the improvised explosive device blew up at a football field in Pattani on July 21.

Four of them suffered minor injuries and were treated for tinnitus and chest pain at the Thung Yang Daeng Hospital.

The blast occurred during the awards ceremony of an event attended by government officials and community leaders in the Nam Dam subdistrict.

Police and explosive ordnance disposal units inspected the scene and found a bomb weighing four pounds (two kilos) buried in the field.

A police spokesman said: 'We have collected evidence at the scene, including explosive parts and security camera footage, to determine who planted the bomb. We believe the attack was intended to create unrest rather than to take lives. Security measures have been enhanced in the surrounding area in response to the explosion.'

Islamic separatist terror attacks target the three southernmost provinces of Thailand - Yala, Pattani and Narathiwat - next to the border with Mulsim neighbours Malaysia. Thai state employees and infrastructure are often hit while attacks on civilians are rare.

Officials believe the conflict dates to a deal in 1909 that the British Empire struck to incorporate the Muslim region into the Siamese mainland.

The region's culture is more similar to Malaysia and dramatically different to Buddhist Thais causing decades of tension that lead to the emergence of separatist groups fighting for independence in the 1960s.

The struggle has continued ever since with more than 7,344 people killed and 13,641 injured between January 2004 and March 2022.

The British Foreign & Commonwealth Office warns against all but essential travel to the region while Canada's government warns its nationals to 'avoid all travel' to the three provinces.