(Reuters) - Authorities arrested a suspect on Friday near the Capitol as part of a terrorism investigation, saying he sought to use explosives, the Justice Department and the Capitol Police said.

Explosives the suspect allegedly sought to use in connection with the plot had been rendered inoperable by law enforcement and posed no threat to the public, Justice Department spokesman Dean Boyd said.

He said the arrest capped an undercover operation in which the suspect had been closely monitored by law enforcement authorities.

Sergeant Kimberly Schneider, a spokeswoman for the U.S. Capitol Police, said in a statement, At no time was the public or congressional community in any danger.

There have been a number of undercover operations in the Washington, D.C., area in recent years in which suspects thought they were plotting to carry out terrorism attacks, but in reality were being monitored by FBI agents.

There were no details on the charges brought against the suspect.