Security Secretary Regina Ip warned on Saturday that the government intends to tighten its vetting of applications for staging public demonstrations.

The comments came a day after more than 200 people staged a public protest calling for greater democracy in mainland China.

Under the terms of a public order ordinance introduced after Hong Kong's handover to China 18 months ago, police have the power to refuse requests if they might pose a threat to social order.

So far most demonstrations and protests have been allowed to continue, but the authorities are worried about the threat to public security posed by Hong Kong's increasing social hardship.

Mrs Ip said that in a climate of rising unemployment people might resort to using excessive means to show their discontent.

The main focus of demonstrations in the past year has switched to the economic crisis, as workers express their anger about wage cuts and job losses. Protesters have called on the government to be more active in dealing with the severe recession.

To a lesser extent, the limited level of democracy in Hong Kong and on the mainland is still an emotive issue.

On Friday more than 200 people marched through central Hong Kong to call for an end to one-party rule in China and the release of jailed dissidents sentenced last month for trying to set up a new political party on the mainland.

During the march, a teenager was arrested for tearing down the Chinese national flag.