TEL AVIV // Attacks against Israelis in Georgia and India on Monday and three explosions in Thailand yesterday suspected to have been carried out by Iranians have spurred worries that a covert war of assassinations between Israel and Iran could escalate out of control.

Israel was on high alert yesterday for possible attacks both at home and at its embassies and offices abroad, a day after the country's prime minister pledged to "act methodically" against what he termed "international terrorism that originates in Iran".

Yesterday, Ehud Barak, the Israeli defence minister, while on visit to Singapore blamed the attacks on Iran and Hizbollah, the Lebanese Shiite militia. The attacks wounded four people in the Indian capital of New Delhi and the Georgian capital of Tbilisi.

He said that both Iran and Hizbollah were "determined ... to act against Israelis in every place in the world" and added that Iran was behind the Bangkok blasts.

Yigal Palmor, a spokesman for Israel's foreign ministry, said yesterday that Israel "cannot rule out any possibility" of a link between the blasts in New Delhi and Tbilisi, and the explosions in Bangkok.

In Bangkok yesterday, news agencies reported that an Iranian man carrying grenades blew off his own legs when he tried to escape police by throwing a grenade at them, just a short time after an explosion took place in a house that the man was renting in the city's centre. A short while later another blast took place on a nearby busy road. Four Thai civilians were injured in the three blasts.

Israel's threats of reprisal and Iran's anger over the daylight assassinations of at least four of its nuclear scientists in the past two years,which it has pinned on Israeli and US agents, could snowball into additional terror acts against each other in the coming months, according to analysts. Israel has launched an intensive campaign in recent years against Iran's nuclear ambitions.

"What we saw thus far may only be the beginning," Ronen Bergman, a veteran Israeli commentator, wrote in Yedioth Ahronoth, Israel's biggest newspaper, yesterday. "The secret war attributed to Israel against Iran and Hizbollah continues in full force. For the time being, Israel is winning by a knockout, but we should not underestimate the other side's determination and capabilities."

According to Mr Bergman, the blasts in Tbilisi and New Delhi are Iran's way of "drawing new rules of play" to avenge the killings of its scientists that seemed aimed at slowing the progress of its nuclear plans.

Iran this week denied involvement in the attacks and has said that Israel itself had carried them out as part of its "psychological warfare" against Iran's nuclear programme and to tarnish Iran's ties with India.

Some analysts said that the apparent failure of the attacks in New Delhi and Tbilisi may prompt attempts to launch more effective assaults against Israelis. In New Delhi, the wife of an Israeli diplomat was injured along with three others when the diplomatic car in which she travelled to pick up her children from school exploded, but authorities said her life was not in danger.

In Tbilisi, an explosive device was discovered in a car of a local staff member of the Israeli Embassy, but was defused by police.

Some Israeli analysts said yesterday that Israel showed no proof for blaming Iran for the attacks and that the government may have been bidding to build up its case against its archenemy's nuclear programme in the international arena.

"Israel in the past few years has always pointed fingers at Iran when such attacks took place," said Haggai Ram, a professor at Israel's Ben-Gurion University. "It may be trying over and over again to frame Iran so as to either tighten the grip of international sanctions or pave the way towards a possible attack on Iran's nuclear sites."