Suspect in terror probe, father arrested at Colorado home

AURORA, Colorado (CNN) - FBI agents have arrested Najibullah Zazi, a 24-year-old Colorado resident and Afghan national suspected in an alleged terrorist plot in the United States.

Zazi and his father, Muhammad Zazi, were handcuffed without incident late Saturday night as authorities raided Zazi's home in the Denver suburb of Aurora.

Their attorney Arthur Folsom was with them at FBI offices in Denver Sunday morning, said Wendy Aiello, the attorney's spokeswoman. Specific charges were not available.

Two more arrests are expected in New York City, a source close to the investigation told CNN.

One of the individuals interviewed several times by authorities is cooperating, the source said.

Earlier in the day, Najibullah Zazi, who had been questioned for the past three days by federal investigators, declined to attend a fourth day of interviews.

Zazi has admitted to having ties to al Qaeda, an administration official familiar with the matter told CNN Friday. Either a plea deal or charges are possible for Zazi, the official said.

Folsom denied the allegations Friday night and said Zazi did not admit to having ties to the terror group. He also said the FBI has not made an offer.

"He never admitted going to a terrorist training camp," Folsom told CNN affiliate KUSA in Denver. "Some of the information in news reports was not true," Folsom said. "There have been no plea negotiations ... they (FBI) haven't made any offer."

Zazi too told The Denver Post on Saturday that he has not admitted any ties to the terrorist group. He also denied taking part in insurgency training in Pakistan or involvement in a terror plot.

"It's not true," Zazi said in a phone interview with the newspaper. "I have nothing to hide. It's all media publications reporting whatever they want. They have been reporting all this nonsense."

He said he lived in Pakistan before moving to New York as a teenager. While in Pakistan, he said, he spends a lot of time with his wife.

"I was there (at her house) the whole time," Zazi said.

The alleged terrorist plot, which came to light this week after raids in New York, may have been targeting a major transportation center, like a large railroad or subway station, sources close to the investigation told CNN on Thursday.

There were plans for an attack, presumably in the New York area, where crowds are large and security screening for non-airport travelers is lax, the sources said.

Two sources familiar with the investigation said that Zazi had video of New York's Grand Central Terminal, a massive junction of rail and subway lines, as well as shops and restaurants, which see an average of more than a half million visitors per day.

A former counterterrorism official said backpacks, computers and maps were found during searches in the New York City borough of Queens, and field tests turned up positive for explosives. But such tests often yield false positives, and the former official was unaware whether more definitive test results had been obtained.

On Wednesday, federal agents searched Zazi's apartment in Denver and another home in the same Denver suburb in connection with the investigation.

A law enforcement official told CNN that diagrams showing how to make bombs were found on the computer that Zazi had with him when he was stopped in New York during a recent visit. But his lawyer denied that was true.

"There's no diagram of a bomb; there's no information like that," Folsom told reporters Thursday as he accompanied his client to his second meeting with federal agents. Had that been the case, he asked, "Do you really think the FBI would have allowed us to walk out of here last night?"

He suggested that Zazi may have drawn investigators' attention "because he stayed at a house owned by an old friend of his who was under observation from the FBI."

Folsom said Zazi stayed in an apartment that was raided after he had driven from Denver to New York on business. Sources close to the investigation told CNN that the Queens raids were spurred by a confluence of events in the city - including the upcoming U.N. General Assembly session and President Barack Obama's Wall Street speech on Monday.

Law enforcement sources with knowledge of the investigation said the Colorado searches were part of a probe that began with Zazi and led to New York.

Agents launched the raids after police stopped Zazi on the George Washington Bridge during his visit to New York City, raising concerns that he would figure out he was under surveillance, the former official told CNN.

FBI Director Robert Mueller told a Senate committee Wednesday that he did not think the investigation had revealed any "imminent danger."

–CNN's Jim Spellman in Colorado and Kathleen Johnston in Atlanta contributed to this report.