A woman was arrested outside the White House Thursday night, after Secret Service officers noticed that she was carrying a gun in a holster, according to reports.

April Lenhart, 23, of Michigan was taken into custody by the U.S. Secret Service at around 8 p.m. EST Thursday. Officers noticed that Lenhart was carrying a 9mm handgun in a holster near the White House's perimeter fence.

President Barack Obama was in the White House at the time of the arrest, having just finished his address to the nation on immigration in the East Room 15 minutes earlier, according to CBS News' White House correspondent Mark Knoller

Ed Donovan, a spokesperson for the Secret Service, told the Washington Post that Lenhart is not cooperating in her interview with authorities, so determining her intentions was proving difficult. Lenhart may face charges as the weapon that she was carrying was unregistered, Mashable reports

Lenhart's arrest comes just a day after Iowa man R.J. “Renae” Kapheim was arrested near the White House with a rifle and 40 rounds of ammunition in his car.

In addition to those two arrests, there have been a series of security incidents at the White House in recent months. On Oct. 22, Dominic Adesanya scaled the fence at the White House, and was taken down by police dogs

Former Secret Service Director Julia Pierson resigned last month, after a man armed with a knife scaled the White House fence and got as far as the executive mansion before being arrested.

This is a developing story. Check back for further updates.