A Clearfield County man who gave undercover federal agents explicit instructions on how to make what he called "bean can grenades" has been arrested on weapons charges.

Bradley Kahle, 60, of Troutville, who said the election of Hillary Rodham Clinton or Barack Obama would prompt a civil war, is being held pending a detention hearing today in Johnstown.

He is one of four men now charged in separate but related investigations by the U.S. attorney's office related to possible militia activity.

The three others, also in custody, were indicted by a federal grand jury last week. They have detention hearings in Pittsburgh today.

According to an eight-page affidavit filed in Mr. Kahle's case in U.S. District Court yesterday, undercover officers have been meeting with him for more than a year.

On Sunday, federal agents served a search warrant at his home, finding 16 improvised explosive devices in a "gun reloading room." They were made out of cardboard cylinders and sealed on both ends with epoxy, with non-electric fusing systems. Agents also found cans of fragmentation and bags of lead shot.

At a previous visit to his home on April 10, according to the affidavit, Mr. Kahle showed two undercover agents several firearms, including assault rifles and a sniper rifle, as well as 5,000 rounds of ammunition.

The information in the affidavit dates to Feb. 1, 2007, when Mr. Kahle described for the undercover officers how to make what he called a "bean can grenade."

Such a grenade, he told them, is made by cutting the top off a bean can and putting an M-1000 firecracker inside. Then, police said, Mr. Kahle described in detail how to attach a fuse and pack shrapnel inside.

"Kahle continued that a tactic for employing a bean can, if raided, is to wait until the police shoot gas through your door," the affidavit said. "The hole made by the gas projectile can then be used to throw a bean can grenade back out at the approaching entry team to kill as many law enforcement officers as possible."

Over the next several months, the undercover agents met with Mr. Kahle multiple times. At one meeting, they talked about a terminally ill person.

Mr. Kahle said if he had terminal cancer he "might as well" shoot a judge or a few police officers, the agent wrote. "You wouldn't want to be near me. SWAT teams included. Bring them all on. ... don't send the kids, bring your very best. Hey, 8 or 10 good bean bombs ... 5 or 600 rounds of ammo and some good equipment. I would be a tough take," he was quoted as saying.

Later, in July, Mr. Kahle told the undercover officers that he made 20 bean can grenades at a time, concealing them in toilet paper and plastic bags, which kept them dry and provided an easy fuel for lighting.

"On Aug. 11, 2007, Kahle advises the [undercovers] that shooting judges, magistrates and chiefs of police would start the doomsday process, or words to that effect."

Then, on March 27, according to the affidavit, Mr. Kahle offered to make the grenades at their next meeting, saying that he had five or six M-1000s.

Two weeks after that, the affidavit said, "Kahle said words to the effect of, that 'if Hillary Clinton or Barack Obama get elected, hopefully they will get assassinated. If not they will disarm the country, and we will have a civil war.'"