An Israeli Cabinet minister says his country will "settle the score" with the perpetrators of a bombing attempt in Bangkok, heightening the state of alert throughout Israel on Tuesday. 

An Iranian man carrying grenades blew his own legs off in the blast. Israeli Defense Minister Ehud Barak said Tuesday the explosion, which wounded four civilians, was an attempted terrorist attack backed by Iran.

Israel has also blamed Iran for a pair of attacks on Israeli diplomatic targets in India and Georgia on Monday.

Speaking on Israel Radio, Public Security Minister Yitzhak Aharonovitch did not mention Iran explicitly, but strongly implied Israel would seek revenge.

"We know who carried out the terror attacks, we know who sent them, and Israel will settle the score with them," he said.

Ehud Barak said Tuesday's explosion in Bangkok "proves once again that Iran and its proxies continue to perpetrate terror."

He 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."

Israel blamed Iran for Monday's attacks in India and Georgia. Officials predicted that those attacks, which targeted Israeli diplomats, were just the first in a wave of assaults on Israeli targets by Iran and its Lebanese proxy, Hezbollah.

"The Iranians and Hezbollah are determined to disrupt Israeli life and to act against Israelis all over the world," Defense Minister Ehud Barak said Tuesday during a visit to Singapore. "They want to strike at Israelis and we must act against this terror front and continue to brace for other challenges we face."

Hezbollah this week marked the fourth anniversary of the assassination of commander Imad Mughniyeh, who died in a mysterious explosion widely blamed on Israel.

Iran, meanwhile, has accused the Israelis of being behind a series of assassinations of nuclear scientists and other sabotage of its nuclear program. Israel, like the West, believes Iran is pursuing nuclear weapons.

In Israel, police spokesman Micky Rosenfeld said security was heightened at public places, foreign embassies and offices, as well as Ben-Gurion International Airport. He says patrols have been stepped up and police were instructed to be especially vigilant.

In India, investigators were searching for what they called a well-trained motorcycle assailant who stuck a magnet bomb on an Israeli diplomatic car in New Delhi, wounding four people, including one critically.

Israel sent forensic scientists from its police force to New Delhi to participate in the investigation, an Israeli government official said. The embassy declined to provide details of the investigation.

"There is day-to-day cooperation between Israeli authorities and Indian security authorities. Very close cooperation," Israeli Embassy spokesman David Goldfarb said.

Iran has denied responsibility for the attack in India, as well as a foiled bombing of an Israeli diplomatic car in Georgia, which appeared to mirror the recent "sticky bomb" killings of Iranian nuclear scientists that Tehran has blamed on Israel.

The bombings have ratcheted already heightened tensions between Tehran and the Jewish state over Iran's nuclear program. Israel doesn't believe Iran's claims that it aims to produce electricity, not bombs, and its threats of a possible military strike have grown more ominous in recent weeks.

An Iranian man carrying explosives blew off his own legs and wounded four other people in two blasts Tuesday in Bangkok, Thai authorities said. A third blast occurred in a nearby house.

Security forces found more explosives in the assailant's rented house in the capital, but it was not known what targets they might have been meant for, Police Gen. Pansiri Prapawat said.

A day earlier, an Israeli diplomatic car was bombed in New Delhi, and Israel blamed Iran for that attack. Authorities did not immediately say if a link was suspected, but Israeli Foreign Ministry spokesman Yigal Palmor said in Jerusalem, "we can't rule out any possibility."

One of the blasts in Bangkok damaged a taxi, and a grenade detonated as the assailant carried it down a sidewalk outside a Thai school, said Col. Warawut Taweechaikarn, a senior police officer in the district.

Photos of the wounded Iranian man showed him covered in dark soot on a sidewalk outside the school strewn with broken glass. A dark satchel nearby was investigated by a bomb disposal unit.

Pansiri said a passport found at the scene indicated the man was Saeid Moradi from Iran. Authorities in Tehran could not immediately be reached for comment.

Three Thai men and one Thai woman were brought to Kluaynamthai Hospital for treatment of injuries, Suwinai Busarakamwong, a doctor there, said.

A third blast occurred inside a rented house on the same road, busy with businesses and apartment blocks.

Last month, a Lebanese-Swedish man with alleged links to pro-Iranian Hezbollah militants was detained by Thai police. He led authorities to a warehouse filled with more than 8,800 pounds of urea fertilizer and several gallons of liquid ammonium nitrate.

Israel and the United States at the time warned their citizens to be alert in the capital, but Thai authorities said Thailand appeared to have been a staging ground but not the target of any attack.Pansiri said that "so far, we haven't found any links between these two cases."

He said Moradi had been renting the house in Bangkok with two other unidentified foreigners.

Immigration police are trying to trace Moradi's movements, but initial reports indicated he had at least traveled to Bangkok from the southern Thai resort town of Phuket on Feb. 8.