Thai investigators believe they have found a link between this week's bomb blasts in Bangkok and New Delhi, a senior security official said on Wednesday, two of three botched attacks Israel has blamed on Iran.
Tehran has strongly denied involvement in the attacks on Monday and Tuesday, including a bomb that failed to explode in the Georgian capital Tbilisi.
Asked whether the explosives used in India and Thailand were the same, a senior Thai security official said they both had the same "magnetic sheets".
"The individual was in possession of the same magnets and we are currently examining the source of the magnet," National Security Council Secretary Wichian Podphosri said.
A man carrying an Iranian passport lost a leg when a bomb he was carrying in Bangkok went off on Tuesday after an earlier explosion, apparently accidental, at a house he was renting. His second leg had to be amputated.
Police said he had been charged with illegal possession of explosives, causing explosions, attempted murder and assaulting a police officer.
The American, British and Australian embassies in Bangkok told their citizens to be vigilant in the light of the explosions but did not advise against travel to the capital.
A day earlier in the Indian capital, a bomb wrecked a car taking an Israeli embassy official to pick up her children from school, police said. The woman was in stable condition on Wednesday after surgery to her spine and liver.
Her driver and two passers-by suffered lesser injuries in the attack which police believe was also a botched job.
The motorbike rider who stuck the bomb on to the car put it on the opposite side to the petrol tank -- if it had been on the tank side it would have been a bigger blast and likely caused fatalities. Media said five people had been detained for questioning.
Israeli officials said an attempt to bomb an embassy car in Tbilisi failed and the device was defused.
Delhi police spokesman Rajan Bhagat confirmed that the blast there was caused by a "sticky bomb". He said witnesses saw a lone motorbike rider attach the device to the right rear side of the car in which the Israeli diplomat's wife was travelling.
He said the device, which was about the size of an iPad, would have exploded about three to five seconds after it was stuck to the vehicle and magnetic fragments were found at the scene.
"This is the first time that this modus operandi has been seen in India," Bhagat told Reuters. "We don't yet have the evidence to point the finger at anybody. We are exploring all possibilities."
Indian media said investigators were scanning records of all Iranian nationals as well as Lebanese students who arrived in the country in recent months.
India police visit Israeli embassy
India said on Tuesday it was still unsure who was behind the attack. It has been pointedly silent on Israel's accusation that Tehran was the culprit.
Police were visiting the Israeli Embassy on Wednesday. Media reported that two Israeli Mossad agents had flown into New Delhi.
New Delhi has good relations with both Iran and Israel, so the attack makes its diplomatic balancing act between the two countries all the more difficult and has thrust the mounting tension between the Middle East rivals on to its doorstep.
Israel is the second-largest supplier of arms to India. But India is Iran's biggest oil buyer, relying on it for about 12 percent of its needs, and it is Tehran's top supplier of rice. On the diplomatic front, India regards Iran as an important partner to protect its regional interests when U.S. troops are withdrawn from Afghanistan.
India's Economic Times questioned why Iran would take the risk.
"The idea that Iran would want to make India a theatre in its rivalry with Israel is far-fetched and does not sit well with the track record of Tehran's relationship with India," it said.
"Iran is in a desperate position because of western financial sanctions to punish it for its nuclear program but it is certainly not desperate enough to alienate New Delhi by ordering an attack on its soil.'
In the Bangkok attack, one bomb went off in the bombers' home. Another was thrown at a taxi that wouldn't take him. The third blew off the bomber's leg when he tried to throw it at police and it either went off before he could throw it or hit something and ricocheted back towards him.
Two other men shared the rented house with him. One was arrested at Bangkok's international airport on Tuesday but the third had slipped past security at the airport and fled to Malaysia, Wichian said.
"Our latest intelligence is that the suspect has escaped from Thailand ... to Malaysia already," Deputy National Police Commander Pansiri Prapawat told a news conference.
Thai police declined to make any link between Tuesday's explosions and the arrest last month of a Lebanese man in Bangkok who, according to the Thai authorities, had links to Hezbollah.
Police discovered a large amount of explosive material in an area southwest of Bangkok at around the time of that arrest. The United States, Israel and other countries issued warnings, subsequently lifted, of possible terrorist attacks in areas frequented by foreigners.
"From investigation, it appears that the incident is more of an individual-focused plot rather than targeting landmark areas," Wichian said. "At the moment, we haven't found any connection to the Lebanese suspect."