BEIJING (Reuters) - The anti-graft watchdog of China's ruling Communist Party has criticised the Beijing government department in charge of Hong Kong affairs for weak leadership and not properly following policy following a routine inspection.

The party's graft-busting Central Commission for Discipline Inspection said late on Friday (Oct 14) that its most recent inspection of the Hong Kong and Macau Affairs Office had found a series of problems. "The party's leadership is not strong or powerful enough, and the enforcement of the relevant policies of the centre is not firm enough," the watchdog commission said in a statement.

The way people are promoted is not conducted in a serious manner, personnel changes are not carried out in a timely way, and party discipline rules not taken seriously enough, it added.

The anti-graft commission's report comes amid mounting concerns among pro-democratic politicians, activists and foreign diplomats that the Central Government's Liaison Office, Beijing's official representative body in the territory, was actively interfering in Hong Kong politics and affairs.

The watchdog's inspection also found "clues" about problems with some senior officials that have been reported up and will be handled, it said, without naming anyone or giving details.

The statement quoted the head of the Hong Kong affairs office, Mr Wang Guangya, as saying he "sincerely accepted" the report and that his agency would "sternly and conscientiously carry out rectification".

China on Friday had also expressed "great indignation and strong condemnation" of two Hong Kong lawmakers who raised the disputed issue of independence at their official mid-week swearing-in ceremony.

The former British colony returned to Chinese rule in 1997 under the so-called "one country, two systems" formula, granting Hong Kong a high degree of freedom and autonomy.

A 79-day "umbrella revolution" in late 2014 demanding Beijing allow full democracy in Hong Kong brought chaos to the streets, and anti-mainland Chinese sentiment has simmered since.

Some fear Beijing's growing role in the city undermines the"one country, two systems" principle.

Critics of unpopular Hong Kong leader, Chief Executive Leung Chun Ying, accuse him to being too close to Liaison Office head Zhang Xiaoming.