Washington, Jan 17 (IANS): The US Capitol Police (USCP) has arrested a man when he tried to cross a checkpoint near the Capitol building in Washington, D.C., armed with a loaded gun and more than 500 rounds of ammunition, according to media reported.

Identified as Wesley Allen Beeler from Front Royal, Virginia, the man told police he was carrying a Glock semi-automatic pistol, which was later discovered to have been loaded with 17 rounds of ammunition and a round chamber ready to fire, Xinhua news agency quoted a CNN report citing a source familiar with the case as saying on Saturday.

Beeler was stopped at a checkpoint at North Capitol and E Street NE, just north of the building, according to the report.

He also had what was described as a fake credential for Wednesday's inauguration event for President-elect Joe Biden.

Police later recovered the pistol, as well as 509 rounds of ammunition, shotgun shells and a magazine for the handgun, CNN said, citing an incident report from the D.C. Metropolitan Police Department.

Beeler was arrested for possession of an unregistered firearm and possession of unregistered ammunition, among other offenses.

The arrest came amid heightened security measures in the national capital ahead of the inauguration.

Up to 25,000 National Guard members have been authorised by the Pentagon for the city, more than the amount of the troops currently stationed in Iraq and Afghanistan combined.

"Every state, territory and the District of Columbia will have National Guard men and women supporting the inauguration," the National Guard Bureau said in a statement on Friday.

The Federal Bureau of Investigation has issued a warning about plans of armed protests from January 16 through January 20 at all the 50 state capitols, and from January 17 through January 20, the day of the inauguration, at the Capitol in Washington D.C.

The heightened security arrangements come in the wake of the attack on the Capitol building on January 6 which took place while Congress was in session considering the ratification of the electoral college votes electing Biden as President and Kamala Harris as Vice President.

Earlier that day outside the Capitol, Trump addressed his supporters during which called for "patriots" to take a stand against the 2020 election results

Five people, including a police officer, were killed during the riots.