Members of a pair of now-defunct mosques in Seattle are being investigated as having possible ties to the international Al Qaeda terrorist network.

An attorney for one of the members confirmed the federal grand jury’s probe on Friday, after a report appeared about it in The Seattle Times.

"The grand jury is looking into a lot of things," lawyer Robert Leen said Friday, declining to be more specific.

Leen represents Semi Osman, 32, who is charged with trying to fraudulently obtain U.S. citizenship and with owning a handgun with the serial number removed. Osman was born in Sierra Leone, holds a British passport and has lived in the United States since the late 1980s, according to Leen.

Osman formerly attended the Dar-us-Salaam mosque, which closed after being damaged in an earthquake in February 2001. Members of that mosque and another that opened nearby after the earthquake have been under investigation, Leen said.

Officials at the FBI and the U.S. attorney's office declined to comment.

Leen said Osman has refused to cooperate with federal investigators. He said his client is not a terrorist, but added: "It's true he was a member of a mosque where it's clear there were some things going on that probably bear some investigation."

Seattle police spokeswoman Deanna Nollette said Friday that several people at the Dar-us-Salaam mosque told officers investigating a 1998 assault that a large number of weapons were stored inside the building. She wouldn't comment further.

Meanwhile, the FBI was investigating Osman's presence at a ranch near Bly, Ore., that agents say may have been scouted by the group of mosque members for a terrorist training camp.

Some intelligence officials estimate there may be as many as 5,000 people in the United States with some sort of connection to Al Qaeda. That number includes those in the "realm of suspicion" and those who may know of terrorist activities but do not participate in them, an official said Thursday on condition of anonymity.

FBI agents are reportedly working with federal Treasury agents to search for U.S. residents who might be advising Al Qaeda terror cells.

The Seattle Times reported Friday that investigators there have identified a half-dozen core members of the suspected terror group and have gathered information on more than 100 others who had dealings with the Dar-us-Salaam mosque.

The newspaper said members of the group have ties to Egyptian-born Abu Hamza Al-Masri, a suspected Al Qaeda recruiter who runs a London mosque and is wanted in Yemen on terrorism charges.

After the Sept. 11 attacks, Al-Masri told The Associated Press that it would be a blessing if God destroyed the United States.

Klamath County, Ore., Sheriff Tim Evinger said federal agents briefed local investigators about the ranch in 1999, before he was elected. He could not say whether they had visited the property, which he described as a 50-acre ranch currently occupied by renters.

Local truck driver Kelly Peterson, who said he had trained horses for the ranch's owner, said FBI agents questioned residents of Bly about Osman three weeks ago.

Peterson said Osman lived at the ranch with a woman and two children for about three months in 1999, adding he had seen nothing out of the ordinary there.

Regarding Osman's stay at the ranch, lawyer Leen said: "I don't think your information is inaccurate." He also confirmed the owner raised sheep there.

Osman was arrested on the citizenship charge in May, following allegations he had entered into a sham marriage in the early 1990s to gain citizenship. Apart from the handgun, investigators serving a search warrant found a visa application for Yemen and a passport from Lebanon.

The passport, issued in 1981, bears a photo of Osman but the name of Sami Samir El-Kassem, according to documents filed in U.S. District Court in Seattle.

Osman is scheduled to go to trial Aug. 12.

Hisham Farajallah, head of the Idris mosque in Seattle — the state's largest and the center of the local Muslim community — said those who established the Dar-us-Salaam mosque aimed to give Muslim workers in downtown Seattle a nearby place to pray.

Farajallah said he had invited Dar-us-Salaam leaders to his mosque a few years ago, but he was not aware of any links to terrorist groups. He said he'd had no contact with leaders since the earthquake.

Local Muslims "are extremely concerned" about a potential backlash from attention now being paid to the investigation, he said.

The Associated Press contributed to this report.