Israel has blamed Iran for three explosions in Thailand after accusing the country of bomb attacks on its diplomats in India and Georgia.
Israeli Defence Minister Ehud Barak said the bomb attacks in Bangkok prove "once again that Iran and its proxies continue to perpetrate terror".
The blasts, which injured five people, come amid growing suspicion Iran is staging a series of revenge attacks for the assassinations of two nuclear scientists.
A picture posted on Twitter showed a wounded man - the bomb suspect - lying on a pavement outside a Thai school.
TV reports suggested an Iranian identification card was found nearby.
It is understood two blasts came from grenades while a third explosive detonated in a home rented by the suspect, named by Thai police as Iranian Saeid Moradi.
Three Thai men and one Thai woman were also injured and treated at the capital's Kluaynamthai Hospital.
Another Iranian was detained at Bangkok's international airport as he attempted to depart for neighbouring Malaysia.
The Bangkok blasts come a day after Iran was blamed for bomb plots in India and Georgia , targeting Israeli diplomats.
Israel believes that Iran may be exacting revenge for the recent deaths of two leading nuclear scientists . Iran has accused Israel of being behind the deaths.
One of the scientists was blown up in his car by a motorbike hitman in January.
That assassination mirrored the method used by a hitman in New Delhi yesterday, when the wife of an Israeli diplomat was critically injured in her car.
Iran has also blamed Israel for the sabotage of military installations and nuclear sites over the past several years.
Mr Barak said that Iran and its Lebanese ally Hezbollah are "unrelenting terror elements endangering the stability of the region and endangering the stability of the world".
The explosion in Thailand occurred just four blocks from the Israeli embassy.
The violence began when a stash of explosives apparently detonated by accident in Moradi's house, blowing off part of the roof.
Police General Pansiri Prapawat said two foreigners quickly left the residence, followed by a wounded Moradi.
"He tried to wave down a taxi, but he was covered in blood, and the driver refused to take him," Gen Pansiri said. He then threw an explosive at the taxi and began running.
Police who had been called to the area then tried to apprehend Moradi, who hurled a grenade to defend himself.
"But somehow it bounced back" and blew off his legs, Mr Pansiri said.
Israel announced that it was raising the state of alert inside its borders, increasing security at airports and embassies.
Sky's foreign editor Tim Marshall said circumstantial details linked today's attack with the one in India and the failed strike in Georgia.
Referring to the possible link, Israeli Foreign Ministry spokesman Yigal Palmor said: "We can't rule out any possibility."
Police Colonel Sittiphab Baiprasert said the Bangkok explosions occurred about 100 metres apart on Sukhumvit Soi 71, next to businesses and apartment blocks.
Thailand has rarely been a target for foreign terrorists, although a domestic Muslim insurgency in the country's south has involved bombings of civilian targets.
Last month, a foreign suspect with alleged links to Hezbollah militants led Thai police to a warehouse filled with more than 4,000kg of urea fertilizer and ammonium nitrate.
Israel and the United States have warned their citizens to be alert in the Thai capital.
Meanwhile, Russia's top general said he expects Iran's enemies to decide in the next
few months how to deal with the Middle Eastern country's nuclear programme.
General Nikolai Makarov, the chief-of-staff, was quoted by RIA news agency as saying he expects "some kind of decision" to be made by the summer".
Moscow has warned adamantly against any use of force to rein in Tehran's nuclear programme.
The West and Israel believe the programme conceals a plan to develop atomic weapons.