BANGKOK, Jan. 22 (Xinhua) -- Three were killed and at least 18 others injured on Monday after a powerful home-made bomb exploded in a fresh food market in southern Thailand's Yala province.

According to local media reports, the blast happened Monday morning when a man parked a motorcycle near a pork stall. The owner of the stall asked him to move it but the man run away first.

The stall owner moved it by herself and a bomb hidden inside the motorbike went off, killing her and another customer on the spot, the reports said.

At least 19 people were wounded as the explosion happened in the busy morning and the blast wave was strong. Goods scattered around and panicked shoppers were crying in fear when police arrived, according to nation TV.

One of the wounded died when hospitalized.

Police said the bomb was detonated with a timing device. They said it has been the first bombing in the market during the past two to three years.

The bombers may be involved in illegal business groups in the province who intend to keep investors and new business away from Yala so that they could corner the market, according to police.

Yala is one of Thailand's three southernmost provinces bordering Malaysia. More than 6,500 people, most of them civilians, have died in separatist violence in the restive southern Thailand since 2004, when resistance to Buddhist rule flared up.

Thailand is predominantly Buddhist but parts of the south, particularly the three provinces of Yala, Pattani and Narathiwat, are majority Muslim, and resistance to central government rule has existed there for decades.