BANGKOK >> Thai authorities arrested a man they believe is part of a group responsible for a deadly bombing at a shrine in central Bangkok two weeks ago, the prime minister announced Tuesday. He said the suspect resembles a yellow-shirted man in a surveillance video who police say planted the bomb.

"It would be great if he were (the bomber). Then we will know who they are, where they came from, who’s behind this," Prime Minister Prayuth Chan-ocha told reporters.

He said the man is a foreigner and was detained in eastern Thailand near the Cambodian border, one of several border crossings where authorities set up checkpoints after the Aug. 17 bombing which killed 20 people, many of them foreign tourists, and injured more than 120.

Prayuth said authorities plan to check fingerprints and conduct DNA tests to establish whether the man is the bomber. Police say they obtained the bomber’s DNA from a motorcycle taxi and a three-wheeled tuk-tuk taxi that he used.

Spokesmen for police and the military junta that rules Thailand both later said the arrested man resembles the suspect they have been seeking for planting the bomb.

No one has publicly claimed responsibility for the attack, sparking an array of theories about who might be behind it. Police have suggested that the suspects were part of a people-smuggling group who held a grudge against Thai authorities.

Speculation has grown that the suspect might be part of a group seeking to avenge Thailand’s forced repatriation of ethnic Uighurs to China in July. Prayuth on Monday linked the two theories, suggesting the bombers might have been involved in smuggling Uighurs out of China.

Prayuth said officials knew from their investigation that people involved in the bombing were about to flee the country and had traced the man to Aranyaprathet district in Sa Kaeo province, a crossing point to Cambodia. The prime minister described the man as a piece in a jigsaw puzzle that would connect various parts of the case, which included a bomb that exploded harmlessly in a river next to a busy pier in Bangkok the day after the shrine blast.

Prayuth warned against speculating about the arrested man until more information is learned.

"Don’t say just yet it’s about this and that. It could affect international affairs," he said. "We have to do a lot of tests, fingerprints. If he is the guy, he is the guy."

"Officials are certain he is a main suspect in this case," national police spokesman Prawuth Thavornsiri said later at a news conference, adding that the authorities are waiting for witnesses to confirm whether he is the yellow-shirted man. He said the man is being held by the military under Article 44 of its interim constitution, which gives the prime minister absolute power to issue any order deemed necessary to keep public order or strengthen public unity and harmony.

Prawuth said three new arrest warrants have been issued in connection with the case, bringing the total to seven. Two were named persons — he could not provide spellings for the names of the men, whose nationalities were unknown — while the third was not identified by name but was described as a Turkish national. He displayed pictures of the three on a tablet computer.

The blast at the Erawan Shrine was unprecedented in the Thai capital, where smaller bombs have been employed in domestic political violence over the past decade, but not in an effort to cause large-scale casualties.

Security officials on Saturday arrested a man during a raid on a Bangkok apartment that contained some bomb-making materials, and Thai military authorities have been interrogating him. He has been linked to the shrine bombing, but the authorities have not yet released his name or nationality.

Arrest warrants were issued Monday for two more suspects, a Thai woman and a man of unknown nationality, after a raid Sunday on a second apartment found more bomb-making materials. Relatives of the woman who had rented the second apartment told authorities that she is innocent and is now in Turkey, married to a Turkish man. The three new arrest warrants announced Tuesday were related to the apartment raided Saturday, police spokesman Prawuth said.

Uighurs are related to Turks, and Turkey is home to a large Uighur community. The Erawan Shrine is especially popular with Chinese tourists, feeding the idea that it could be a target for people who believe the Uighurs are oppressed by China’s government. Beijing says some Uighurs are Islamist terrorists, and among them is a group that has been smuggled out of China to join Islamic State fighters in Syria.

The suspect arrested Saturday had a Turkish passport, though Thai authorities say it was fake. At his apartment, they seized at least 11 passports that appeared to be Turkish, among more than 200 passports in all.

A Turkish Foreign Ministry official said Monday that reports that the woman wanted by Thai police may be in Turkey and other allegations about a Turkish connection were "speculation" and that the ministry would not comment on speculation.

The official said he had no information about the woman and could not confirm that her husband is Turkish.

The official spoke on condition of anonymity in line with government rules that bar officials from speaking to journalists without prior authorization.