South Wales Police said the 17-year-old boys were detained while abroad and that an investigation is underway into the circumstances surrounding their travel to Thailand.
South Wales Police on Facebook said:
“This is a very concerning time for the families and wider community.
“We currently have limited information on the arrests, but officers are gathering as much information as possible.”
Anyone with information or concerns is asked to contact South Wales Police and quote reference 2600200125.
