Iconic Mao portrait in Beijing apparently vandalized with paint

The huge portrait of Communist China's founder Mao Zedong that looms over Tiananmen Square in Beijing is believed to have been vandalized with a black paint-like material, Kyodo News found Thursday even though security is tighter than usual as the country opened its parliament session a day before.

Police were seen swarming the scene around 11:30 a.m. while two men in a crane were cleaning off what appeared to be a blackish taint on the lower left part of the iconic portrait that hangs over the entrance to the Forbidden City.

The portrait of the late leader was quickly fixed and areas around the square returned to normal in the afternoon.

The square, one of the most popular tourist sites in China, is under heavy security each day as many central political buildings, including the leadership compound Zhongnanhai and the Great Hall of the People, the country's parliament building, are located close to it.

The square is also the site of the 1989 bloody crackdown by the Chinese government on democracy protesters.

On Wednesday, China's top legislature kicked off its annual session during which petitioning by citizens who are frustrated with corruption among officials and other problems often takes place in the heart of the capital.