BANGKOK: China, the US and Britain were among several countries that have issued travel advisories for Thailand after three bombs exploded here two days ago.
The explosions Tuesday rocked the Bangkok's business hub, wounding five people.
Two Iranians were held, while a third suspect, also an Iranian, was nabbed in Kuala Lumpur Wednesday after he managed to flee the country.
The authorities are also looking for a fourth suspect, a woman who allegedly arranged a rented accommodation for the three accused.
Iran has condemned the blasts, Xinhua reported.
Deputy Prime Minister Yuthasak Sasiprapha said Thursday that the explosions were a security issue and there was no evidence to classify them as a terror attack.
"The government views the blasts as having impacted on the national security," the online edition of The Nation newspaper quoted him as saying.