KARACHI, Pakistan -- In a foiled suicide bomb plot, Islamic militants planned to ram an explosives-laden Volkswagen into a car carrying U.S. diplomats in Karachi, Pakistan police said Sunday.
Police said they arrested three men Friday and Saturday and seized about 250 sacks of ammonium nitrate, a fertilizer used in explosives. They said the suspects had been trained at a camp in Afghanistan run by Islamic militants fighting Indian rule in the disputed province of Kashmir.
"They were preparing for the attack on American diplomats in the coming days, and they had the car bomb ready," provincial police chief Kamal Shah told a news conference.
"They were surveying for appropriate place" on one of the main roads in this southern port city, frequently used by diplomats, he said.
Shah said one of the suspects, Asif Zaheer, was linked to a May suicide bombing outside a hotel in Karachi that killed 14 people, including 11 French engineers. "Asif Zaheer is an expert in explosives, and he was the man who prepared the car for suicide bombing at the Sheraton Hotel," Shah said.
Police said they had no immediate evidence of links between the foiled plot and the al-Qaida terror network.
"We cannot rule out a network of al-Qaida in Karachi," he said. "But there is no concrete evidence yet."
The plan apparently involved loading the nose of the rear-engine Volkswagen bug with explosives, waiting for a diplomatic vehicle to pass and ramming it to detonate the bomb.
The would-be attackers apparently decided on their plan after a June bombing outside the U.S. Consulate in Karachi killed 12 Pakistanis but no Americans.
'"Assessing the strength of the U.S. consulate building, we decided to target American diplomats as they traveled on city roads,'" Shah quoted Zaheer as telling police.
He said Zaheer had no apparent links to the consulate attack but wanted to drive the planned suicide car bomb personally to ensure the plot succeeded.
The 250 88-pound sacks of fertilizer -- not all of which would have been used in the car bombing -- could produce a huge explosion. Shah said Zaheer told investigators it was twice the amount of explosives used in the May bombing.
Earlier Sunday, authorities had announced the arrests of three men Saturday in connection with the May suicide bombing, but it was not immediately clear if they were same three suspects discussed in the press conference.
Shah said that six suspects are still at large in that attack.
He said Zaheer and the other suspects were trained in Afghanistan at the camp of the militant group Harakat Jihad-e-Islami.
The militants demand that Kashmir, divided between India and Pakistan, be reunited and either be given independence or be allowed to join Islamic Pakistan. India's part of Kashmir is the majority Hindu country's only state dominated by Muslims.
Police have arrested several other people in connection with the May attack, and have apprehended dozens of others alleged to have taken part in a spate of attacks on foreigners in Karachi.
Many of those arrested earlier are reportedly members of the Harkat-ul-Mujahideen Al-Almi extremist group.
Earlier reports had suggested the suspects might be linked to Lashkar-e-Jhangvi, a group blamed for the June consulate bombing, as well as attacks on several churches. But Shah said that appeared not to be the case.
Zaheer was also wanted in connection with the killing of a television producer in the capital, Islamabad, earlier this year.
"These arrests are a major breakthrough," Shah said. "We have not only prevented a major terrorist attack but also succeeded in solving an old case."