WASHINGTON (AFP) - US police arrested a female suspect Monday after three iconic Washington landmarks, including the Lincoln Memorial, were vandalised with green paint.

A spokeswoman for the US capital's Metropolitan Police Department confirmed the woman's arrest to AFP, but gave no other details.

The Smithsonian Institution said "hard-to-notice, greenish paint" was discovered on Monday on a bronze statue of its first secretary Joseph Henry outside its headquarters on the National Mall.

"US Park Police looked at the paint to see if it matched what was thrown on the Lincoln Memorial" overnight Thursday, Smithsonian spokeswoman Linda St.

Thomas told AFP.

Elsewhere, fresh green paint was found Monday in two chapels within the National Cathedral, a spokesman for the Episcopal church said.

Back at the Lincoln Memorial, workers with high-pressure hoses continued to carefully erase remaining bits of green paint on the white marble sculpture of Civil War president Abraham Lincoln.

"It's going to take several days," US Park Service spokeswoman Carol Johnson told reporters.