A second foreign suspect has been arrested in connection with the deadly bombing at a Bangkok shrine in August, Thailand's prime minister has said.
The male suspect was arrested in Sa Kaeo province, east of Bangkok on the border with Cambodia, Prayuth Chan-ocha told reporters.
He described the man as "a main suspect".
A foreign man was arrested in Bangkok on Saturday over the blast at Erawan Shrine, which killed 20 people.
Thai military authorities have been interrogating the 28-year-old man, but they have not yet released his name or nationality.
Bomb-making materials and forged passports were found at the apartment where he was detained in Nong Jok on the outskirts of Bangkok, and he has been charged with possessing illegal explosives, police said.
It is unclear whether either of the two arrested men is the suspect seen on a security camera leaving a backpack at the crowded shrine shortly before the bombing on 17 August.
Thai authorities have issued three more arrest warrants - making seven in total.
'A main suspect'
"We have arrested one more, he is not a Thai," Mr Prayuth told journalists after his weekly cabinet meeting, calling him "a main suspect and a foreigner".
Images of the detainee in military custody showed a tall, thin man with trimmed facial hair, wearing sunglasses and a baseball cap.
At a news conference, Thailand's national police spokesman Lt Gen Prawut Thavornsiri said the man was intercepted as he attempted to cross the border illegally into Cambodia.
Thai media circulated a photo of a Chinese passport which was claimed to belong to the man detained on the border. On the passport, he is identified as Yusufu Mieraili, 25, from Xinjiang province - home to a significant Muslim Uighur population.
One police investigator also identified him as "Yusufu", Thai media said.
Thailand controversially repatriated more than 100 Uighur Muslims to China in July.
Thai authorities have also released details of the three new suspects for whom they have issued arrest warrants. One suspect is an unidentified Turkish man, another a foreign man named Ahmet Bozoglan and a third a foreign man named Ali Jolan.
All face charges of illegally possessing explosives.
On Monday, Thai police issued arrest warrants for two other suspects - a 26-year-old Thai Muslim woman, Wanna Suansan, and an unnamed foreign man.
However, a woman who claims to be Ms Suansan told AFP from Turkey that she had last been in Thailand three months ago.
She said she was "shocked" to have been named as a suspect.
Also on Tuesday, police said they had transferred 16 officers - including senior officers - from their posts in Bangkok districts for negligence.
An additional six immigration officers were transferred from their posts in Sa Kaeo, where Tuesday's arrest took place, Reuters reported.
Police chief Somyot Pumpanmuang was quoted as saying the immigration officers had been transferred because it had emerged that foreigners had been able to enter the country illegally.
The transfers came just a day after the same police chief said he would reward his own men for making the first arrest.