Thailand's tourism industry has raised concerns that Tuesday's bombings in Bangkok may scare tourists away from the country.

Kongkrit Hiranyakit, president of policy and planning for the Tourism Council of Thailand, said the police must come up with evidence that the bomb attack was not related to terrorism for tourists' fears to be allayed.

Thai authorities have been trying to play down the bombings. Thai police are charging Iranian suspects with criminal offenses instead of terrorist acts. Thailand's Foreign Minister Surapong Tovichakchaikul said no evidence links the incident to terrorism.

Police said the attackers' explosives were not intended for terrorism but likely intended for targeting individuals, because they were not powerful enough to cause large destruction.

Still, 14 countries have issued travel warnings against Thailand, including the United States, Japan, South Korea and some other key sources of tourists to the country.

If the suspects were proven to have links to terrorism, the impact on Thailand's tourism industry would linger until the Songkran festival in mid-April, Kongkrit said.

"The tourism mood is damaged and hotel reservations for Songkran are about to begin," he added.

Songkran is the country's most celebrated festival when people threw water at each other to celebrate the new year in Thai traditional calendar.

Thailand's Tourism and Sports Ministry reportedly decided to postpone its push for visas on arrival to Iranian visitors. The ministry has been trying to push the Immigration Department to start issuing 15-day visas on arrival for Iranians because their arrivals to Thailand have grown 20-30 percent in the past three years.

The blasts caused a psychological impact on tourists, but had little effect on room reservations, the Tourism Authority of Thailand said in a statement.

The number of foreign tourists visiting Thailand may drop by about five to ten percent, or 100,000 to 200,000 people, which means an estimated revenue loss of five to ten billion baht, trimming gross domestic product (GDP) growth by between 0.1 and 0. 2 per cent, according to a survey by the University of the Thai Chamber of Commerce.

Four Iranians ran out of a rented house in downtown Bangkok after an explosion. One of them threw a bomb at a taxi, injuring the driver and three pedestrians. He threw a second bomb at a police car but it bounced back and severed his legs.

Thai police have arrested two suspects. A third suspect who fled to Kuala Lumpar is detained by Malaysian police and to be extradited. A female suspect, who rented the blasted house, is at large. Police officers said that some more suspects could be involved.