Monday's bombing in Thailand was "unlikely" to have been the work of an international terror group, the Thai government has said.

Col Winthai Suvaree, a spokesman for the ruling military junta, said this was the preliminary conclusion reached by investigators.

However, authorities say the prime suspect in the bombings was foreign.

The attack on the Erawan Shrine in central Bangkok on Monday evening killed 20 people and injured scores.

Police say that at least 10 people are suspected of involvement in the attack.

National police chief Somyot Pumpanmuang said he believed the attack was planned at least a month in advance.