The Hong Kong Civil Human Rights Front the NGO that planned the actions posted a message on its Facebook page Friday indicating it had been notified by the police of the ban on two rallies and one march that the group hoped to hold next Tuesday.
According to the police's reply to the front, the ban was necessary in order to "safeguard public safety, public order and others' rights and freedom", Efe news reported.
The front was behind three mass protests since the ongoing anti-government protest movement erupted in June, with each pulling in at least one million demonstrators.
It has planned to hold a rally at Victoria Park on Hong Kong Island and then a "No National Day But National Calamity March" to be followed by another rally in a garden in the city's central financial district.
The police ban reflects part of the Hong Kong authorities' effort to gear up for October 1 an all-important day for Beijing that marks the 70th anniversary of the founding of the People's Republic of China.
As the Asian financial hub has been convulsed by more than three months of unrest associated with the movement, which was sparked by a controversial extradition bill, the Hong Kong government is taking pains to keep any disruptions and chaos at a minimum on October 1, including cancelling the annual National Day fireworks.
( With inputs from IANS )