MUMBAI, India (CNN) -- Indian authorities Wednesday defused a bomb at Mumbai's Chhatrapati Shivaji Terminus railway station -- one of the first locations targeted in last week's terrorist siege, authorities told CNN's sister network in India, CNN-IBN.
Mohammed Ajmal Kasab at Mumbai's Chhatrapati Shivaji Terminus railway station. more photos »
Security officials told the network that the location of the bomb at the station, formerly known as Victoria Terminus, was provided by Mohammed Ajmal Kasab, 21, who is in police custody and who has been identified as the only surviving gunman.
The officials said the explosive device was made from RDX, a powerful explosive. Four other RDX bombs planted during the well-coordinated attacks have also been defused and police believe there are no more, the officials said.
Earlier Wednesday the police official leading the investigation said the terrorists spent the last three months in Pakistan training and planning their strike.
At least 179 died when a band of gunmen attacked 10 targets in Mumbai. Most of the deaths occurred at the city's top two hotels, The Oberoi and the Taj Mahal. Watch survivor recount Mumbai horror »
The attacks sparked three days of battles with police and Indian troops in the heart of India's financial and entertainment capital.
Mumbai Joint Police Commissioner of Crime Rakesh Maria said the information had come from his interview with Kasab, who Maria said is from the Faridkot village in the Okara district of Pakistan's Punjab province. He is the son of Mohammed Amir Kasab, Maria added. Watch claims attackers came from Pakistan »
But Pakistan's President Ali Asif Zardari told CNN on Tuesday that India has provided no "tangible proof" that the suspect is a Pakistani national.
Maria said Kasab spend the last year-and-a-half training at various camps run by Lashkar-e-Tayyiba -- a Pakistan-based terror group allied with al Qaeda.
Kasab told police he joined the group, known by its acronym LeT, six months before he began training.
The group was banned in Pakistan in 2002, after an attack on the Indian parliament that brought the nuclear rivals to the brink of war. The training primarily took place in the Kashmiri city of Muzaffarabad, he said.
The group has denied responsibility for the Mumbai attacks.
"He was told things like, 'You'll come in through this door, then go over here, then go out through that door,'" Maria told CNN. "Very very detailed explicit instructions. The gunmen were hand-picked, but there were no examinations per se. While in the camps they all had code names."
All of the attackers were trained in Kashmir by former Pakistani army officers, but apparently did not know each other, Maria said.
During the last three months of the training, which focused on Mumbai, Kasab was "shown photographs of the locations he was to target," including one of Mumbai's main railway stations and the hospital.
Police have identified Kasab as the clean-shaven young man photographed in a black t-shirt carrying a weapon during the attack on Mumbai's Victoria Terminus train station.
Maria said Kasab joined LeT because he was poor, but he expressed surprise at how easily he was "brainwashed" into joining the terror group.
Maria made his comments as Mumbai prepared for memorial rallies scheduled Wednesday, as well as in several other Indian cities, including New Delhi, Kolkata, Hyderabad, Bangalore and Chennai.
Earlier Wednesday U.S. Secretary of State Condoleezza Rice told a press conference in New Delhi that the attacks were "the kind of terror in which al Qaeda participates" -- although The Associated Press reported Rice as saying that it was too early to determine who was responsible.
She said Pakistani President Asif Ali Zardari had pledged to follow leads in last week's terrorist attacks "wherever they go."
"I think that is a very important commitment on the part of Pakistan," Rice said. But she said Pakistani authorities must move with "a real sense of transparency, a real sense of action, a real sense of urgency."
India says the coordinated strikes originated in Pakistan, and has renewed its call for Pakistani authorities to hand over about 20 wanted Indian militant leaders who have taken refuge in Pakistan. It has been demanding the extradition of some of those leaders since a 2001 attack on India's parliament that brought the south Asian nuclear rivals to the brink of war, for which Lashkar-e-Tayyiba has been blamed.
Rice's visit came as Pakistani President Asif Ali Zardari told CNN's Larry King he believed the perpetrators were "stateless actors who have been operating all throughout the region."
"The state of Pakistan is in no way responsible," Zardari told King. "... Even the White House and the American CIA have said that today. The state of Pakistan is, of course, not involved. We're part of the victims, Larry. I'm a victim. The state of Pakistan is a victim. We are the victims of this war, and I am sorry for the Indians, and I feel sorry for them." Watch Zardari discuss Pakistan's stance »
On Tuesday Mumbai's police chief Hasan Gafoor said that he never received a warning of an impending seaborne attack on Mumbai -- despite Indian security forces telling CNN that U.S. officials warned the Indian government in New Delhi on two occasions about such a threat.
According to a U.S. counter-terrorism official, New Delhi was warned about a potential maritime attack on Mumbai at least a month before the massacre.
But Gafoor said: "(The warning) that terrorists could arrive by sea was from an intelligence report of last year that only said terrorists could attack Gujarat or industries in the south." Mumbai is located in Maharashtra state, which borders Gujarat state.
He added that the 10 attackers hijacked a trawler in the Pakistani port city of Karachi -- about 575 miles (925 km) north of Mumbai -- and came ashore at Mumbai in dinghies.
Gafoor said a global-positioning system, or GPS, found with the attackers showed they had come from Pakistan.
Intelligence officials told CNN-IBN that the captain of the trawler was found dead, lying face down with his hands bound behind his back. Four crew members who had been on board were missing, they said.
CNN's Ram Ramgopal, Harmeet Shah Singh and Nic Robertson contributed to this report.
All About India • Pakistan • Mumbai • Terrorism
Lashkar-e-Toiba (LeT), a militant Islamic fundamentalist group based in Pakistan, has been implicated in last week's Mumbai attacks in India.

Rakesh Maria, a commissioner with the Mumbai Police, said that the sole surviving attacker, whom he identified as Mohammed Ajmal Kasab, has admitted spending three months in a Lashkar-e-Toiba camp preparing the attacks. Kasab, who is reported to be 21 years old, told police that he spent a total of eighteen months training at various LeT camps.
Some of the aftermath of the attacks
Meanwhile, John Michael McConnell, the United States Director of National Intelligence, indirectly implicated LeT. In a speech at Harvard University, he said that the same group responsible for the 2006 Mumbai train bombings was behind last week's attacks. LeT has also been blamed for the attack on the Parliament of India in late 2001

"The same group that we believe is responsible for Mumbai had a similar attack in 2006 on a train and killed a similar number of people," said McConnell without naming LeT. "If you examine the groups we think are responsible, the philosophical underpinnings are very similar to what Al-Qaeda puts out as their view of how the world should be. It is a continuation."

Commissioner Maria said that the training took place in Muzaffarabad, Pakistan, near the disputed Kashmir region. Kasab received very specific instructions, according to Maria.
Sites of the attacks in Mumbai
"He was told things like, 'You'll come in through this door, then go over here, then go out through that door,'" Maria told CNN's Nic Robertson. "Very, very detailed, explicit instructions. The gunmen were hand-picked, but there were no examinations per se."

India has also said that Kasab named known LeT leader, Yusuf Muzammil, as the mastermind behind the attacks.

US Secretary of State Condoleezza Rice visited the Indian capital of New Delhi on Wednesday.

"Pakistan needs to act with resolve and urgency and cooperate fully and transparently," said Rice. "That message has been delivered and will be delivered to Pakistan."

Analysts cited by Reuters are saying that India will not resort to a military response over the Mumbai attacks.

"The military option has never been an option, because the military can't guarantee you an outcome," said Manoj Joshi, an editor at the ''Mail Today''. "We have been there, done it, and it doesn't work." In 2002, India threatened military action after the parliament attack.

"If you want a solution to Afghanistan, you have to lean on Pakistan to shut down all jihadist operations," said Siddharth Varadarajan, an editor at ''The Hindu''. "You have to tackle the root cause, which is the attitude of the Pakistani military. That is the silver bullet."