Please answer a question about the following article about 2008 Summer Olympics torch relay:

Chinese officials canceled the torch relay ceremony amidst disruptions, including a Tibetan flag flown from a window in the City Hall by Green Party officials. The third torchbearer in the Paris leg, Jin Jing, who was disabled and carried the torch on a wheelchair, was assaulted several times by unidentified protestors seemingly from the pro-Tibet independent camp. In interviews, Jin Jing said that she was "tugged at, scratched" and "kicked", but that she "did not feel the pain at the time." She received praise from ethnic Chinese worldwide as "Angel in Wheelchair". The Chinese government gave the comment that "the Chinese respect France a lot" but "Paris [has slapped] its own face."

Who put a flag of Tibet out of the window at City Hall?
Green Party officials.