Hong Kong (dpa) - Concurrently with the celebration of China's 70th birthday, tens of thousands have taken to the streets in Hong Kong for democracy and human rights.

Subsequently, clashes between radical protesters and the police took place in several places. Activists blocked roads, threw paving stones, set fire and threw incendiary devices. The officers use tear gas, batons and water cannons.

Police also reported at least two sharp warning shots, Hong Kong newspaper South China Morning Post reported. Observers expected the riots to worsen until the evening.

The demonstrators marched through the streets of the Chinese Special Administrative Region despite a ban on the authorities. "Freedom for Hong Kong," shouted the mostly black-clad demonstrators and the hymn of the protest movement. In other places in the former British crown colony with its approximately seven million inhabitants, protesters came together for peaceful protests.

At the same time, celebrations for the 70th anniversary of the People's Republic of China had started under high security in the morning. Barred by the public, invited guests followed a ceremony in the city's exhibition center, which was broadcast to the closed rooms.

A guard of honor hoisted the national flag on the golden Bauhinia statue, a landmark of the city. Two helicopters with a large Chinese and a smaller Hong Kong flag flew over the harbor along the Hong Kong skyline.

Protesters call for an independent investigation into police violence in the five-month protests, an amnesty of the more than 1,500 people arrested so far, a withdrawal of their protests as "riots" and free elections.

"We fight for freedom and democracy," said a protester named Ramon. The Communist Party did not grant people free elections, and freedom of assembly and freedom of speech would continue to be restricted.

In anticipation of the riots, the authorities had already closed in the morning a few streets and subway stations in the city center. At least 6,000 police officers were on hand, according to the South China Morning Post. Several large shopping centers and hundreds of shops in the city remained closed; Some hotels advised their guests to stay indoors.

Hong Kong's head of government Carrie Lam, hated by the protest movement, did not spend the holiday in the city. Together with a large delegation she had traveled to the big military parade in Beijing.

Hong Kong authorities had forbidden a planned large Tuesday protest march in advance. Nevertheless, the democracy movement had announced several protests for the day. Already during protests at the weekend in Hong Kong had come again to heavy clashes between police and demonstrators.

Since its return to China in 1997, Hong Kong has been governed autonomously by its own constitution. The Hong Kong people are under China's sovereignty but, unlike the people of the Communist People's Republic, enjoy more rights such as freedom of expression and assembly, which they now fear.