Thai authorities have not ruled out any group, including elements opposed to the military government, for a bomb blast in Bangkok that killed 22 people, but officials said the bombing did not match tactics used by insurgents in the south.
Eight foreigners were among those killed by the bombing at a popular shrine on Monday evening, an attack that could hurt Thailand's vital tourism industry.
Police teams were deployed to the blood-splattered site early on Tuesday, some wearing white gloves and carrying plastic bags, searching for clues.