If and when there was a clearance action, he said, neither he nor the police wanted any students hurt.

And in an interview with TVB's On the Record - his first such appearance in the public eye since a civil disobedience push started three weeks ago - Leung insisted he will not quit office.

"I believe that it would not help resolve the matter [even if] I stepped down," he said.

"This is because students and Occupy Central participants have demanded the National People's Congress Standing Committee withdraw its decision and the implementation of a civil nomination mechanism, which are impossible to achieve," he said, referring to Beijing's approach to political reform and the 2107 election of chief executive. But the Federation of Students, Occupy Central and Scholarism, in a joint response, said the government was "out of control" for firing tear-gas at unarmed protesters and for unilaterally terminating dialogue with the students.

As the chief executive, Leung should take responsibility for what happened and resign, they said.

Police fired tear gas and used pepper spray during a series of protests on September 28. That was the same day Occupy Central was launched after students launched a week-long boycott of classes on September 22. Leung said the decision was made by the police commander at the scene based on the situation at that time.

Asked what was the purpose of using tear gas, Leung responded: "We have relied on the police's professional judgment and training." But he added: "We are not passing the responsibility to the police."

Leung said nobody who had been at home or in an office watching events on television could make a judgment call on the police commander's decision.

As for who decided to cease using tear gas, he answered: "I was involved in the whole development. And the police did not use tear gas again when it was unnecessary, when the crowd did not storm the police lines again." Police said earlier that minimum force was used to maintain a distance between the protesters and officers and to prevent injury.

On Occupy Central, Leung said it was a "mass movement" that has spun out of control. "The latest developments show that no one can decide the direction the movement goes or its pace," he said.

Leung cautioned, however, that the movement should not be regarded as a "revolution."

Asked why authorities have still not cleared the protesters, Leung said that while the government was aware of its duty to enforce laws "this incident is special and the government is concerned about students and their demands."

The government and the police, he argued, have shown great tolerance in handling the situation.

In a joint statement, the Hong Kong Journalists Association, RTHK staff associations, Ming Pao and Next Media criticized Chief Executive Leung Chun- ying for only accepting the interview with TVB.

A spokesman for Leung's office said the interview was arranged after taking into account his working itinerary.