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.
Analysis: Jonathan Head, BBC News, Bangkok
The latest statement by the Thai authorities casts little new light on the mystery surrounding Monday night’s bombing – but it does appear to rule out the involvement of known organisations like al-Qaeda.
The Thais say they have been consulting with intelligence agencies from allied countries, and from their discussions they believe the attack is not linked to international terrorism.
That leaves the possibility that it was carried out by local perpetrators, although there is no group in Thailand with a track record that suggests their involvement. Or it may have been the work of a hitherto unknown group.
The Thai police are still looking for three men seen in a grainy security camera video at the shrine just before the blast and have issued an arrest warrant and requested help from Interpol. However, they have no names or nationalities, and it is possible these men are no longer in the country.
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An arrest warrant has been issued for one unidentified man seen on CCTV footage leaving a backpack at the shrine shortly before the blast.
A reward of one million baht ($28,000; £17,950) has been offered for information leading to the main suspect’s arrest.
The Thai police have also appealed to Interpol for help in catching the perpetrators.
Correspondents say information from the Thai authorities about the investigation has at times been confusing or contradictory.
The fact that the crater at the scene was filled in within 24 hours with a view to getting the shrine reopened as soon as possible has also raised questions around the effectiveness of the probe.
The Hindu shrine is popular with Buddhist and Chinese tourists, but the spokesman said authorities did not believe Chinese people had been the “direct target” of the attack.
Most of the victims of Monday’s attack were Thai, but nationals from China, Hong Kong, the UK, Indonesia, Malaysia and Singapore were among the foreigners killed.
Prime Minister Prayuth Chan-ocha has called the bombing the “worst ever attack” on Thailand.