Thai police have said that two men who were arrested in connection with a deadly bomb blast in Bangkok were the ones who carried out the attack and there is enough evidence to prosecute them.

Authorities are confident that the two men in custody, identified as Adem Karadag and Mieraili Yusufu, are responsible for the bombing at the Erawan Shrine on August 17 that killed 20 people and injured more than 120, said National Police Chief Somyot Poomphanmuang. Officers are seeking at least 15 other people they believe are linked to the case.

Police have said the motive for the attack was revenge by a people-smuggling network against Thai authorities for breaking up their operation.

"Today, police are confident Adem and Yusufu are the real attackers," Mr Somyot told reporters. "Adem is the yellow-shirted man who planted the bomb. Yusufu is the one who exploded the bomb."

The police chief said the case against the two men was supported by CCTV footage, witnesses, DNA matching and physical evidence. He said the pair had also offered confessions.

On Saturday, police got the two men to carry out a re-enactment of the bombing at the crime scene as well as their getaway. Such re-enactments are a routine police procedure in Thailand.

Police spokesman Prawut Thavornsiri announced late on Friday that arrest warrants had been issued for a total of 17 people believed to be linked to the case.

With the new police findings that the two arrested men were believed to have actually carried out the bombing, the charges against them - previously involving the possession of military materials and explosive substances - were upgraded to murder, attempted murder and conspiracy to use explosives to kill, Mr Prawut said.

Mr Somyot said the strength of the evidence had forced the two suspects to confess. He described the police investigation as complete now that the two alleged bombers had been identified.

However, many questions remain unanswered about the case. Police have not detailed what action triggered the alleged violent revenge, and Mr Somyot has suggested that the people smugglers "might have hired" another group of people to carry out the attack. The names and nationalities of some of the others still being sought are still unknown.

Even the two arrested men's true identities remain uncertain. Adem Karadag was arrested when police raided an apartment in Bangkok on August 29, where they also found bomb-making materials and a large quantity of fake passports, including a bogus Turkish passport carrying the photo of the suspect and the name Adem Karadag.

His lawyer claims he is Turkish, but that his real name is Bilal Mohammed and that he was only seeking a job in the region. Karadag is the man in a yellow T-shirt who police say video footage showed planting the bomb at the shrine.

Mieraili Yusufu was the name on a Chinese passport carried by a suspect arrested in eastern Thailand, near the Cambodian border, on September 1. Police said his fingerprints matched those found on a bottle containing bomb-making material discovered in a raided apartment.

The passport, verified as real, identified him as being from China's western Xinjiang region. That fact, and his name, strongly suggested he is a member of China's Uighur ethnic minority.

Early speculation about the bombing suggested it might be the work of Uighur separatists who were angry that Thailand in July forcibly repatriated more than 100 Uighurs to China, where it is feared they face persecution. The theory was bolstered by the fact that the Erawan Shrine is popular among Chinese tourists, who figured prominently among the victims of the bombing.

Thai officials, who insist the attack had no political element to it, have conceded that the gang worked to smuggle Uighurs out of China. At least four of the suspects still at large have been tentatively identified as Turkish, which also ties the case to the smuggling of Uighurs, who often emigrate to Turkey, with which they have an ethnic kinship.