Story highlights Paint is splattered on a leg and base of the 19-foot Abraham Lincoln statue, police say

The Lincoln Memorial is closed until the paint can be cleaned up

No timeframe of the closure is given

Officials are hopeful that the chamber containing the Lincoln statue at the Lincoln Memorial, which was vandalized overnight, can be reopened sometime Friday, National Park Service spokeswoman Carol Johnson told reporters.

The memorial's portico -- the columned area outside the chamber -- should be reopen before that, in the late morning, she said.

Workers are cleaning the paint that had been splashed onto part of the marble statue, she said.

Vandals splashed green paint on the base of the statue overnight, prompting officials to temporarily close the marble fixture on Washington's National Mall, authorities said.

Police were alerted just before 1:30 a.m. and found paint splattered on the leg and base of the 19-foot-tall statue of Abraham Lincoln, U.S. Park Police Capt. Steven Booker told CNN on Friday. There were no discernible letters or markings.

The memorial will be closed until it is cleaned up, Booker said.

The memorial, one of the more iconic features of Washington, honors the 16th U.S. president. The marble statue of a seated Lincoln resides in nearly 100-foot-high columned marble building facing the U.S. Capitol and the Washington Monument.

Photos: Photos: Lincoln Memorial through the years Photos: Photos: Lincoln Memorial through the years Federal officials announced that philanthropist David Rubenstein will give $18.5 million to restore and upgrade the Lincoln Memorial, shown here during a wreath-laying ceremony celebrating the 16th President's 207th birthday on Friday, February 12. Hide Caption 1 of 13 Photos: Photos: Lincoln Memorial through the years Sean Kennealy of the National Park Service points out drawings on a concrete pillar Monday, February 15. The renovation will include providing visitors with a look at graffiti left by construction workers building the monument. Hide Caption 2 of 13 Photos: Photos: Lincoln Memorial through the years Cranes lift blocks of marble to the top of the structure in 1914. Hide Caption 3 of 13 Photos: Photos: Lincoln Memorial through the years Workers install the statue of President Abraham Lincoln in 1920. Hide Caption 4 of 13 Photos: Photos: Lincoln Memorial through the years People skate on the frozen Potomac River in front of the memorial in this undated photo. Hide Caption 5 of 13 Photos: Photos: Lincoln Memorial through the years The Lincoln statue looms over visitors in 1962. Hide Caption 6 of 13 Photos: Photos: Lincoln Memorial through the years The Rev. Martin Luther King Jr. delivered his "I Have a Dream" speech from the steps of the memorial on August 28, 1963. Hide Caption 7 of 13 Photos: Photos: Lincoln Memorial through the years Anti-war protesters splash around in the Reflecting Pool during a rally against the Vietnam War in May 1970. Hide Caption 8 of 13 Photos: Photos: Lincoln Memorial through the years Planes fly over the memorial during the inauguration of George H.W. Bush in January 1989. Hide Caption 9 of 13 Photos: Photos: Lincoln Memorial through the years Marine One flies over the Reflecting Pool with President Bill Clinton on board in May 1999. Hide Caption 10 of 13 Photos: Photos: Lincoln Memorial through the years In August 2010, tourists pass the marker commemorating King's 1963 speech on the east steps of the Lincoln Memorial. Hide Caption 11 of 13 Photos: Photos: Lincoln Memorial through the years Algae forms on the water in the Reflecting Pool in September 2012. Hide Caption 12 of 13 Photos: Photos: Lincoln Memorial through the years Lincoln's statue was vandalized with green paint in 2013. Hide Caption 13 of 13

More than 6 million people visited the Lincoln Memorial in 2012, the National Park Service says

Dedicated in 1922, it has been the site of a number of protests and gatherings, including the 1963 March on Washington, during which Martin Luther King Jr. gave his famous "I Have a Dream" speech from the steps of the memorial.