A woman demonstrating outside the White House on Thursday night was arrested for carrying a gun, a Secret Service official told Fox News, moments after President Barack Obama began a speech unveiling sweeping reforms to the U.S. immigration system.

April Lenhart, 23, of Mount Morris, Mich., was arrested around 8:30 p.m. local time after two plain-clothed agents spotted her carrying a 9 mm handgun in a holster around her waist while demonstrating along the north fence of the White House complex, Secret Service spokesman Robert Hoback said in an email, adding that the Uniformed Division officers had immediately been notified by the agents.

Although Lenhart was accompanied by another unidentified individual, police officials only arrested the 23-year-old, Reuters reported.

The Michigan native was charged with possession of an unregistered firearm and ammunition and carrying a pistol without a license. But according to CBS News, she has been uncooperative during questioning, refusing to make statements to authorities.

Lenhart's arrest came shortly after Obama began detailing his executive action plans on immigration, which will ease the threat of deportation for some 4.7 million undocumented immigrants, from the East Room in the White House.

Meanwhile, recent months have seen a series of security breaches at the White House.

On Wednesday, a man was arrested outside the White House after Secret Service agents found a hunting rifle and ammunition in his car. He was charged with illegal possession of a firearm.

In September, a man jumped the fence and made it inside the building before getting caught, leading the director of the Secret Service, Julia Pierson, to resign in October.

In the fiscal years 2009 through 2014, a total of 40 people illegally crossed into restricted areas outside the White House complex, according to the agency's thorough account to Congress, which included documents highlighting the difficulty of protecting the White House from mentally ill individuals.

That's more than twice as many as Pierson intimated in testimony before Congress in late September, according to The Inquisitr.