Hong Kong (CNN) -- Hundreds of thousands of protesters flooded Hong Kong's streets Sunday, shortly after the city's new chief executive was sworn in during a ceremony with Chinese President Hu Jintao on the 15th anniversary of Hong Kong's return to Chinese sovereignty.
Despite the humid weather, organizers reported that 400,000 protesters turned out for the annual July 1 protest against what they say is the ever-encroaching hand of the Chinese central government in the city's affairs and freedoms.
It was the largest turnout since the estimated 500,000 protesters who marked the same date in 2003. Police put the figure at a much lower 63,000 people.
The march capped a weekend of opposition to the appointment of Chief Executive Leung Chun-ying — also known as C.Y. Leung -- who was voted in by an electoral college of 1,200 influential figures in Hong Kong with Beijing's approval, as well as the suspicious death of Tiananmen dissident Li Wangyang. These recent flashpoints topped the list of ongoing grievances about the lack of universal suffrage, soaring housing prices, worsening pollution and a growing wealth gap.
Amid megaphone-led chants for Leung to "step down" and myriad banners and costumes mocking Leung as a cunning "wolf," some protesters waved the former Hong Kong flag used under British rule -- a gesture used to symbolize the erosion of the city's freedoms following the 1997 handover.
Other protesters used images of the Hello Kitty cartoon to mock Leung's claim that Hello Kitty stickers in his home showed that previous tenants were responsible for his home's illegal — and highly controversial -- building structures, which came to light last week. Draping a Hello Kitty sash across his chest, Hong Kong artist Kacey Wong steered an all-pink army tank labeled as the "cultural bureau," mocking Leung's proposed new government department.
Significantly, Leung's swearing-in ceremony on Sunday was fully conducted in Mandarin rather than the local Cantonese language, a move that did not go unnoticed by citizens sensitive about the encroachment of China's national language in Hong Kong.
"How completely alienating. If we have to watch a leader we didn't elect get sworn in, we could at least have it conducted in our own language," tweeted user @supercharz, Charmaine Mok.
Leung ignored reporters' requests for comment about the protests as he exited the ceremony.
The carefully orchestrated ceremony was interrupted during Hu's remarks by a heckler who shouted slogans calling for a redressing of the Tiananmen Square massacre and the establishment of a democratic Chinese nation before he was bundled out by security.
The ceremony capped Hu's three-day visit to Hong Kong. Hu left the city before the July 1 march commenced at 3 p.m. local time.
However, hundreds of protesters gathered outside Hu's hotel on Saturday, where they were enclosed within unusually high barricades that towered more than 2 meters high, which had not been used in Hong Kong since World Trade Organization protests in 2005. Several protesters and journalists were pepper-sprayed in the scuffle.
During Hu's tour at the Kai Tak cruise terminal the same day, an Apple Daily reporter who yelled out a question about the Tiananmen Square massacre was removed by police from the press area and questioned under a stairwell.
Meanwhile, the Hong Kong protests went unmentioned in the extensive coverage of the handover anniversary presented by Chinese state-run television station CCTV and news agency Xinhua. CNN's television broadcasts about the handover anniversary in Hong Kong were blacked out in mainland China on Sunday and Monday, while BBC World's coverage was also censored after it veered from Leung's inauguration remarks to mentioning concurrent protests.
A photo circulating widely online Sunday picturing fireworks exploding in Victoria Harbor over the heads of protesters captured the divide between the government's representation of the sentiment surrounding the handover anniversary and the discontent brewing amid many citizens.
In a statement addressing the July 1 march, the Hong Kong government said it "fully respected people's rights to take part in processions and their freedom of expression and would listen to their views in a humble manner."
It went on to say that the government will "uphold the core values of Hong Kong and protect the freedom and rights of the people."