An apple core thrown over a White House fence prompted security officials to clear a portion of Pennsylvania Avenue, the Secret Service said.

Parts of the avenue in front of the White House were cleared after the incident shortly before 4:30 p.m. Saturday.

Uniformed U.S. Secret Service officers keep watch outside the White House in Washington, November 17, 2015. CARLOS BARRIA / Reuters

The White House was briefly placed into lockdown, which is standard practice any time there is a security concern. The lockdown was lifted after about five minutes.

U.S. cities have stepped up security in the wake of last week’s terror attacks in Paris that killed 130 people, for which the terror group ISIS has claimed responsibility.

The Secret Service said the woman who threw the apple core over the fence from E Street was taken in for questioning but will not be arrested or charged.