eavily armed U.S. Capitol police stand guard outside the U.S. Capitol after at least one person was shot in the Capitol Visitor Center March 28, 2016 in Washington, DC. The Capitol was placed in 'lock down' following the shooting. Win McNamee/Getty Images WASHINGTON (Reuters) - Washington police said on Sunday they detained a man wielding an assault rifle who entered a pizza restaurant that was the target of fake news reports it was operating a child abuse ring led by Democratic presidential candidate Hillary Clinton and her top campaign aide.

An unidentified 35-year-old man was being held for questioning after police were called to the Comet Ping Pong restaurant in Washington near the Maryland border, said Aquita Brown, a spokeswoman for the Metropolitan Police Department in the nation's capital.

Brown said no shots were fired and there were no injuries.

A Reuters witness at the restaurant with his one-year-old child said it was crowded when the gunman entered, with many families dining.

It was unclear whether the man was aware of the internet postings about Comet. Police said there was no active investigation of child abuse allegations there.

Last month, various media outlets, including the Washington Post and New York Times, reported on internet postings that had sparked death threats against the owner of the restaurant. The attack on Comet was considered an example of how fake news reports that proliferated during the election year impacted people's lives.

The police department said in a statement that it is "monitoring the situation and aware of general threats being made against this establishment."

"We’ve directed the staff to notify MPD should they receive specific threats or have concerns about their safety."

The Reuters witness who was inside Comet at around 3 p.m. ET said he was paying his bill when he saw a man entering the restaurant's front door. "It appeared to us he had a long rifle with him. We scattered," he said.

The restaurant began to empty and some staff also exited, according to the witness.

A police department tweet later stated, "Suspect armed w/assault rifle taken into custody."

(Reporting By Richard Cowan; Editing by Mary Milliken)