BANGKOK — Police in Thailand say the bodies of six people were found Tuesday in a luxury hotel in downtown Bangkok and poisoning is a possibility.

Investigators said the bodies were foaming at the mouth, an officer from the Lumpini police station said on condition of anonymity because he wasn’t authorized to release information.

Bangkok police chief Lt. Gen. Thiti Sangsawang identified the dead as two Vietnamese Americans and four Vietnamese nationals and said there were three males and…