Policemen inspect a taxi damaged in an explosion in Ekamai area in central Bangkok — Reuters

“They are charged with causing an illegal explosion in a public area and attempting to kill police officers and members of the public,” Foreign Minister Surapong Tovichakchaikul told reporters.

Iranian suspects behind a failed attack in Bangkok aimed to assassinate Israeli diplomats, a Thai official said on Wednesday, in the third bomb plot to shake world capitals this week.

The explosions in Bangkok on Tuesday came a day after bombers targeted Israeli embassy staff in India and Georgia, with a female diplomat seriously wounded in New Delhi, in attacks for which Israel accuses Iran.

One of the Iranian suspects, named as 28 year old Saeid Morati, had his legs blown off as he hurled an explosive device at Thai police while fleeing an earlier blast at a house in Bangkok on Tuesday, officials said.

“These three Iranian men are an assassination team and their targets were Israeli diplomats including the ambassador,” a senior Thai intelligence official told AFP, speaking on condition of anonymity.

“Their plan was to attach bombs to diplomats' cars.” Iran, which has already denied responsibility for the Delhi and Tbilisi incidents, said it had no link to the Bangkok blasts and blamed what it called “elements linked with the (Israeli) Zionist regime”.

Iranian Foreign ministry spokesman Ramin Mehmanparast,“rejected the accusations by the Zionist regime of implication (of Iran) and accused that regime of trying to harm the friendly and historic relations between Iran and Thailand,” according to the Iranian state television website.

Thai bomb squad experts were called out to the Sukhumvit Road area in the east of the city in response to an apparently unintended blast at a house rented by an Iranian, after which three men were seen fleeing, authorities said.

One of the men hurled an explosive device at a taxi, which refused to stop, and then tried to throw another at police, triggering a blast at the side of a busy road which tore off his legs, they said.

Authorities detained a second Iranian man trying to board a flight out of the country while the third suspect is believed to have fled to Malaysia.

Explosives and magnets were later found inside the partially destroyed house, police said.

Individuals appeared to be the target of the botched plot as the devices were not powerful enough to cause large-scale damage, said Thailand's National Security Council chief Wichean Potephosree.

“Yesterday's incident was caused by current international tensions in world politics,” he told a news conference.

“It's happening not only in Thailand but also elsewhere. Thailand's weak point is that we are an open country to help our economy so I urge all Thais to be vigilant and inform the authorities if they see anything suspicious.”

Bangkok has been on the watch for a terror attack since police last month charged a Lebanese man suspected of planning a strike, following a US warning that tourist areas might be targeted.

Thai authorities alleged the Lebanese man had links to Hezbollah, an Iranian- and Syrian-backed Muslim Shiite group that is blacklisted as a terrorist organisation by Washington.

Israel was quick to accuse Iran of involvement in Tuesday's blasts in Bangkok.

“The attempted attack in Bangkok proves once again that Iran and its proxies are continuing to act in the ways of terror and the latest attacks are an example of that,” Israeli Defence Minister Ehud Barak said.

The blast in New Delhi blew up a car, critically wounding the Israeli diplomat and her Indian driver.

In Tbilisi, an Israeli embassy employee found a bomb on his car and contacted police who were able to defuse the device before it detonated, according to Georgia's interior ministry.

Thai police said they had found no direct link between Tuesday's bombings and the earlier threat but had received a separate warning from intelligence sources about a potential new attack and declined to speculate on any ties of the suspects with militant groups.

The United States condemned the Bangkok blasts and voiced concern about a worldwide “uptick” in such violence, including some with alleged links to Iran.

“We're concerned about it. Some of these (attacks) have been linked to Iran,” State Department spokeswoman Victoria Nuland said.

The Bangkok blasts are another blow to the kingdom's tourist-friendly image, which was badly dented last year by devastating flooding across much of the country, as well as rounds of rival political protests in recent years.