WASHINGTON  Secret Service agents on Friday arrested a man in Mississippi who wrote a series of entries in an Internet chat room saying he intended to kill President-elect Barack Obama, the Justice Department said.

The man, Steven J. Christopher, who is from Wisconsin, was arrested in Brookhaven, Miss., for making threatening entries on Jan. 11, 15 and 16, said Dunn Lampton, the United States attorney in Jackson.

The entries, which included racial and anti-Semitic remarks, were on a Web site that features information and articles about extraterrestrials, government conspiracies and unexplained physical phenomenon.

In one Jan. 11 entry, according to the Justice Department, Mr. Christopher wrote: “Yes, I have decided I will assassinate Barack Obama. It’s really nothing personal about the man.”