A security fence is seen around the perimeter of the White House in Washington, DC, March 18, 2017. / AFP PHOTO / SAUL LOEBSAUL LOEB/AFP/Getty Images (Saul Loeb/AFP/Getty Images)

Two people were in custody Monday and at least one was arrested after they threw a sign and a notebook over the White House fence, authorities said.

The incident happened about 10:30 a.m. Monday.

Areas around Pennsylvania Avenue and Lafayette Square near the White House were closed for about an hour to pedestrians. D.C. police and fire units also responded, according to a Twitter message from the Secret Service.

The U.S. Secret Service said just before 11:30 a.m. in another Twitter message that the incident was "cleared" and that one man was arrested and taken to D.C. Police. They did not give details as to what the sign said.

Their message went on to say that both items were "deemed nonhazardous."