Authorities are still trying to identify the vandals who splashed green paint on the Lincoln Monument in Washington D.C. early Friday. The memorial remained closed for around 12 hours for cleaning.

 Lincoln Memorial reopened after it was temporarily closed to allow the National Park Service maintenance crew to clean up the splattered paint. The police are continuously trying to review the surveillance footage to identify the vandal behind the act. The 12-hours of cleaning process cleared most of the paint marks. However some stains remain which will be cleaned over the weekend and on Monday, according to NBC News.

The monument, inaugurated in 1922, is one the several structures built to honor an American president. Lincoln's Memorial is one of the most famous in the nation's capital. Millions of people visit the memorial every year. Carol Bradley Johnson, a spokeswoman for the National Mall and Memorial Parks division of the National Park Service, called the incident "heartbreaking."

The Historic preservation crew spent hours using the pressurized hoses and a chemical paint remover to remove the stains on the statue, the pedestal and the floor, Johnson told BBC News.

"It is not permanent damage," Johnson said. "Our historic preservation crew knows exactly what they need to do."

The act of vandalism quickly gained nationwide attention. The National Park Foundation asserted on the need to preserve the nation's national parks and the Lincoln Memorial from any such occurrence. The foundation joined with Gannett-owned WUSA9 and started a fund to raise money for the cause, reports USA Today.

Donors can either send a text message or access the foundation's official site . One can also share photos of their donations on Twitter with the hashtag #RespectLincoln.

"In honor of our nation's more than 400 national parks, the National Park Foundation is raising funds to protect and preserve the Lincoln Memorial and other national parks that have experienced vandalism," officials from the National Park Foundation said in a statement. "Your generous donation will make it possible to help the National Park Service restore, protect and safeguard these treasured places, so they may be experienced today and for generations to come."