BANGKOK, Thailand -- An assassination attempt against Prime Minister Thaksin Shinawatra almost succeeded on Thursday (August 24), but he "left an hour earlier than usual" from home, while police seized a potential car bomb and an army officer who drove the vehicle.

"It's my lucky day. I have been varying my travel times after the intelligence services told me people were trying to kill me," the prime minister said, according to the Nation newspaper.

"If I hadn't left an hour earlier than usual, I might not be here now."

Two sticks of dynamite, each weighing half a kilogram, and a large amount of fertilizer were discovered inside the vehicle, some police said.

Police Major General Aswin Khwanmuang, deputy chief of the Central Investigation Bureau, said a 4.5-kilogram bomb was found in the car, indicating the fertilizer alone may have weighed 3.5 kilograms.

Police Bomb Squad Chief, Colonel Kosol Ngampramuan, described however a 50-pound bomb, plus 10 sticks of dynamite inside in the car, according to the Associated Press.

"The explosives were not yet assembled," the Nation newspaper said, indicating suspicions that the dynamite was to be combined with the fertilizer to make a extremely powerful car bomb.

"Bomb experts have destroyed the [components of the] bomb, and the car is being towed to a safe place for further checking," police told reporters.

The vehicle was cruising back and forth near Thaksin's home, and one of his security guards became worried and asked police to follow the car and investigate, according to a Thai television news report.

Police reportedly discovered the car parked near Thaksin's residence, in a street that his motorcade usually follows.

Police caught the alleged fleeing driver, Thawatchai Klinchana -- an army lieutenant in the Internal Security Operations Command (ISOC) -- and took him for interrogation at the police Crime Suppression Division.

Thawatchai was arrested and charged with possessing explosive materials, including TNT, without a permit.

An investigation was launched to determine if Thawatchai would be charged with an assassination attempt against the prime minister, plotting to detonate a car bomb, or other serious charges linked to Thaksin's claim that it was an imminent against him, police said.

The unscathed prime minister immediately fired Pallop Pinmanee, deputy chief of ISOC, after the incident.

"Yes, I signed an order to fire him this morning," Thaksin told reporters, without elaborating.

"The man [Thawatchai] told police that he is General Pallop's driver," Police Major General Aswin Kwanmuang told reporters -- though some Thai news reports said that job may have ended a few months ago.

"You know me. If I was behind it, I would not have missed," said a visibly nervous Pallop, after Thaksin disciplined him.

"I wouldn't have sent Thawatchai to drive around, as reported, the Prime Minister's residence. I would have just set it off without giving away any prior warnings," Pallop said while denying involvement.

"The explosive was being transported, not assembled to be detonated," Pallop said, apparently trying to play down the danger.

ISOC was earlier blamed for faulty intelligence-gathering abilities in grappling with ethnic Malay Islamist guerrillas fighting for autonomy or independence in southern Thailand -- though Muslim rebels did not immediately appear to be linked to the bomb-carrying vehicle.

Pallop said he assigned the arrested driver to southern Thailand a few months ago, to work for ISOC as an intelligence officer.

"I learned about the plot to harm me and my family two weeks ago," Prime Minister Thaksin told reporters.

"I know the people who are behind the plot, but I cannot say who they are. It is the duty of investigators to find out."

Big, mass-produced, "Wanted Dead or Alive" posters portraying Thaksin appeared on Bangkok's streets in March, waved by protesters to needle the prime minister -- a close ally of U.S. President George W. Bush and a former police officer who received a PhD in Criminal Justice at Sam Houston State University in Texas.

The popular poster's "reward" was 73 billion baht (1.8 billion U.S. dollars), the amount Thaksin's family pocketed, tax-free, by selling their Shin Corp. telecommunications empire in February to the Singapore government's investment wing, Temasek Holdings.

The sale attracted allegations that Thaksin manipulated tax loopholes to enrich himself, sparking weeks of street demonstrations demanding his immediate resignation.

Thaksin insisted he and his family did nothing illegal, and that other Thai investors also use tax laws to maximize profits.

Most of the sale's profit went to Thaksin's family, especially his son and daughter. Earlier, when Thaksin became prime minister, he transferred many assets to them, and to household servants and staff.

Thaksin hopes to contest a national election tentatively scheduled for October 15, and was widely expected to be re-elected.

Copyright by Richard S. Ehrlich, who has reported news from Asia for the past 28 years, and is co-author of the non-fiction book of investigative journalism, "HELLO MY BIG BIG HONEY!" Love Letters to Bangkok Bar Girls and Their Revealing Interviews. His web page is http://www.geocities.com/asia_correspondent