"The type of improvised explosives they used were the same. The type that was attached to vehicles," Prewpan said, confirming that an investigation into a magnetic strip found in Bangkok was the same type used in New Delhi.
The comments were the first confirmation by Thailand that the explosions this week were part of a terror plot to be carried out in the country. It raises concerns that even Thailand - a sunny tourist destination long perceived to be off the global terror map - is equally vulnerable to attacks.
A red flag was raised last month, with the arrest of a Lebanese-Swedish man with alleged links to Hezbollah who led police to a warehouse near Bangkok packed with more than 8,800 pounds of urea fertilizer and other materials that could be used to make bombs.
Israel and the United States at the time warned their citizens to be alert in Bangkok.
The U.S. Embassy said that foreign terrorists may have been looking to attack tourist areas in Bangkok and Thai media reported the attacks were aimed at Israeli targets, including the Israeli Embassy. Thai authorities insisted that Thailand was a staging ground for attacks but not the target.
Thai officials say it is not clear if the two incidents are connected.
Authorities in Thailand are still trying to determine if the Iranian men were part of a larger terror group. Two of the men were detained in Bangkok on Tuesday after fleeing the destroyed house, while a third was arrested Wednesday in neighboring Malaysia after boarding a flight from Bangkok to Kuala Lumpur overnight.
Israel accuses Iran of waging a campaign of state terror and has threatened military strikes on Iranian nuclear facilities, while Iran has denied responsibility for all three plots this week.
On Monday in New Delhi, an explosion tore through an Israeli diplomatic vehicle, wounding the driver and a diplomat's wife. On the same day in the former Soviet republic of Georgia, authorities say attackers planted an explosive device on the car of a driver for the Israeli Embassy, but it was discovered and defused before going off.
Israeli Prime Minister Benjamin Netanyahu denounced the violence.
"If this aggression isn't halted, ultimately it will spread to many other countries," Netanyahu said in Israel's parliament Wednesday. He convened his Security Cabinet to discuss terrorism against Israel and "Iran's involvement in repeated attempts to attack Israeli targets," his office said.
Israeli Ambassador to Thailand Itzhak Shoham told The Associated Press in an interview Tuesday that the similarity of the bombs found in Bangkok and New Delhi has led Israel to believe the groups are linked.
"We can assume that there is the same network of terror," he said.
Iran's Foreign Ministry spokesman Ramin Mehmanparast called the allegations baseless and said Israel was trying to damage his country's relations with Thailand and fuel conspiracy theories. Iran has blamed the Jewish state for the recent killings of Iranian atomic scientists.
Thai police have named the Iranians in custody here as Saeid Moradi, who lost at least one leg in a self-inflicted grenade blast as he tried to flee police, and Mohammad Kharzei, who was detained Tuesday as he tried to board a flight to Malaysia.
Each man faces four criminal charges: possession of explosives, attempted murder, attempted murder of a policeman and causing explosions that damaged property.
Thai officials identified the third suspect as Masoud Sedaghatzadeh, and officials in Malaysia said he was arrested there Wednesday.
Malaysia federal police spokesman Ramli Yoosuf said Sadaghatzadeh was being investigated for terrorism-related activities linked to the Bangkok blasts, but could not say whether he would be extradited to Thailand.
At least five bombs were identified in Bangkok. The first blew off the roof of the men's house, and Moradi detonated two others. He hurled one at a taxi when its driver refused to give him a ride, and threw the other at police to fend them off. The taxi driver and three other Thais were wounded in the taxi blast.
When police searched the men's house in the busy Sukhumvit Road area, a bomb squad found and defused two explosives, each made of three or four pounds of C-4 explosives inside a pair of radios.
The type of explosives suggested they would have been used to target individuals rather than large crowds or buildings, said National Security Council chief Wichean Potephosree.