A federal grand jury is investigating a group affiliated with two defunct Seattle mosques for possible ties to the Al Qaeda terror network, an attorney for a former mosque member said Friday.

"The grand jury is looking into a lot of things," said attorney Robert Leen, who declined to be specific.

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

Meanwhile, the FBI was investigating Osman's presence at a ranch near Bly, Ore., that agents reportedly believe was scouted by the group for a terrorist training camp.

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.

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 "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." He would not comment further.

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 declined to comment further and referred questions to the FBI, which declined comment.

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 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 here have identified a half-dozen core members of the suspected terror group but 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.

Al-Masri told The Associated Press following the Sept. 11 attacks 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 to office, but he could not say whether they had visited the property. He described the property as a 50-acre ranch currently occupied by renters.

Kelly Peterson, who said he had trained horses for the ranch's owner, told the AP Friday that 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, and that 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. Besides 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 area 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.