NATIONAL FBI ALERT: Man wanted for possession of explosive materials is on the run




Ryan Kelly Chamberlain, II (Photos: FBI)



SAN FRANCISCO -- The FBI is asking for the public's help to find a San Francisco man accused of having explosive materials at his home.

FBI agent Peter Lee told KTVU Sunday that Ryan Kelly Chamberlain, 42, was the focus of a FBI operation a day earlier that closed off the block around his apartment for 15 hours.

Ryan Kelly Chamberlain II, 42, was last seen Saturday south of the city, the agency said in a statement.

"We don't know the intent or motive yet," FBI agent Peter Lee told reporters, stressing there was no threat to public safety.

Chamberlain was described as a white male, 6 feet, 3 inches tall, and 225 pounds, with brown hair and blue eyes. He was last seen driving a white 2008 Nissan Altima with either a California or Texas license plate.

He should be considered armed and dangerous, the FBI said.

Chamberlain's block was closed for some 15 hours over the weekend as investigators searched and cleared the area, KTVU reported.

It was not immediately clear what led them to that site.

Both the owner and manager of the apartment building where Chamberlain lived told KTVU that he gave no outward signs of suspicious behavior. Building owner Martin Harband said Chamberlain had rented a ground floor apartment for the past two years.

CNN also contributed to this article.