HONG KONG, Oct. 1 (Xinhua) -- Hong Kong on Tuesday saw various forms of activities, both official and grassroots, marking the National Day, with taxis putting up national flags and hikers chanting patriotic slogans.

Despite rioters' threats to mar the festive occasion with sabotage, a range of patriotic activities were held across the city and attended by thousands of residents.

On Tuesday morning, more than 1,000 local hikers mounted the Dragon's Back, a ridge in the southern part of Hong Kong island, while chanting "China add oil!" and "Hong Kong add oil!" all the way.

Another group of Hong Kong youth unfurled a huge national flag on top of Tai Mo Shan, the highest peak in Hong Kong, and displayed another banner to mark the 70th anniversary of PRC.

About 300 people took to the sea to celebrate the National Day. At around 9:00 a.m. local time, when two boats sailed into the middle of the Victoria Harbor, people on board stood up and sang the national anthem. "Long live the motherland!" They chanted and applauded.

Ellen Tsang, coordinator of this activity, hoped that the activity could inject positive energy into the community and encourage Hong Kong youths to contribute to the country.

On Tuesday morning, more than 2,000 taxis hoisted national flags and made a parade across Hong Kong.

The organizer Taxi Drivers and Operators Association said the parade represented its 60,000 cabbies' love for the country and Hong Kong, and their support for actions by the HKSAR government and police to stop violence and restore peace.

The Hong Kong Jockey Club on Tuesday also held a "National Day Cup" horse race at its Sha Tin Racecourse Stand as part of its annual National Day celebration.

A national flag protection campaign was also launched by Safeguard Hong Kong, a community group formed by different sectors of the society, in Edinburgh Place, Central, with singing of national anthem and display of a giant national flag.

The campaign was launched after recent unrests saw several cases of national flag desecration by rioters.

A flag-raising ceremony was held at the Golden Bauhinia Square Tuesday morning to mark the 70th anniversary of the People's Republic of China (PRC), followed by a grand reception hosted by the government of the Hong Kong Special Administrative Region (HKSAR).

During the glorious course of national development, "Hong Kong has leveraged its strengths to serve our country's needs and benefitted from its rapid development," said Acting Chief Executive Matthew Cheung in his speech at the reception.

Talking about the unrest that has plagued Hong Kong for more than three months, Cheung said violence and confrontation are never solutions to problems.

"We need more than ever the solidarity of all Hong Kong people to work towards the same goal, seek common ground and accommodate differences," he said.