U.S. Capitol police officer Angel Morales keeps watch in front of the Capitol in Washington, in this February 17, 2012, file photo. An Ohio man claiming sympathy with Islamic State militants was arrested on Jan. 14, 2015, in connection with a plot to attack the U.S. Capitol with guns and bombs, court documents disclosed. Reuters /Kevin Lamarque/Files

An Ohio man who was allegedly planning to bomb the U.S. Capitol was arrested Wednesday by the FBI, ABC News reported. The man, Christopher Lee Cornell, allegedly vocalized his support for "jihad" on Twitter, and "allegedly posted statements, videos and other content expressing support for ISIS," also known as the Islamic State, or ISIL, according to ABC.

Cornell's alleged social media postings tipped off investigators, NBC News reported. Cornell then dealt with an undercover agent, and "was never in a position to carry out his plan," NBC said, citing an unnamed official.

Cornell was allegedly plotting "to set off pipe bombs in the U.S. Capitol and shoot people as they fled," CNN reported, citing a copy of the complaint filed against Cornell in Ohio.

FBI agents from the bureau's Cincinnati-Dayton Joint Terrorism Task Force said the 20-year-old Cornell had "purchased two semi-automatic rifles and about 600 rounds of ammunition," according to WCPO-9, Cincinnati's ABC news affiliate.

“He did not think he would receive specific authorization to conduct a terrorist attack in the United States, but stated that he wanted to go forward with violent jihad and opined that this would be their way of supporting [terrorists],” FBI Special Agent T.A. Staderman said, according to WCPO-9's report.