Americans concerned about personal safety following the terror attacks of Sept. 11 are taking matters into their own hands, applying for permits to carry concealed weapons and buying guns in increasing numbers.

In Colorado last month, officials say they conducted more than triple the number of background checks for concealed-weapons permits than they did a year earlier. One sheriff even waived the $100 fee as a patriotic gesture and asked applicants to donate the money to the victims of the terrorist attacks instead.

The newfound interest in firearms is repeating itself across the country. In California and several other locales, officials report that gun sales rose 30 percent in the weeks following the terror attacks. In Texas, Washington and Oklahoma the number of people filing for concealed-weapons permits has been about 25 percent above normal.

Gun shop owners and the buyers flocking to them say they feel more vulnerable these days.

"If they can't keep them off the planes, doesn't that mean they can't keep them out of my backyard either?" Mark Lawler, a recent shopper at Texas Guns in San Antonio, Texas, asked.

Wayne LaPierre, executive director of the National Rifle Association, says NRA firearm-safety courses, often a requirement for obtaining a permit, are booked solid through the end of December in many areas.

"People want to be safe and they don't want to be left defenseless and they want to cope with their fear of an unknown future with protection rather than without," LaPierre said.

State-by-state or nationwide figures on the number of concealed-weapons permits actually issued are not available because local jurisdictions are responsible for the permits and the sign-up process varies.

But the National Instant Criminal Background Check System, an FBI division that conducts instant checks for firearms sales and concealed-weapons permits, reports that it conducted 937,042 checks in the month after the attacks — up 21 percent from the same period last year.

Joshua Orrison, 23, of Loveland, applied for a permit at the beginning of October, shortly after Larimer County Sheriff Jim Alderden suspended the $100 fee as a patriotic gesture. He works with youth groups such as 4-H and wanted additional protection while on outings, but said the terrorist attacks and the fee waiver persuaded him to apply.

"With the things going on, you never know what's going to happen," Orrison said.

Gun-control advocates urged caution among people buying firearms and authorities issuing the permits.

"There's no evidence thus far that this has been a street battle. It's been on the scale of large attacks and, in that respect, I think that this response doesn't match the reality," said Tom Mauser, whose son Daniel was killed during the Columbine High School rampage in 1999.

The Colorado Bureau of Investigation does the background checks required for gun purchases and concealed-carry permits in the state. In September, it did background checks on 217 people who had applied for permits, up from the 142 background checks in September 2000. Last month, the agency did 586 concealed-carry checks, up from 184 in October 2000.

Alderden has scheduled 1,559 to be fingerprinted for concealed-carry permit applications since mid-September. He issued about 870 permits in the 2 years before the attacks, and has issued 145 permits since Sept. 24.

The Associated Press contributed to this report.