Education minister Christine Choi said on Saturday that new rules on teachers' conduct won't limit their freedom of speech.

The Education Bureau on Thursday published a set of guidelines listing things teachers should and should not do.

Speaking on a radio programme, Choi said teachers can still speak freely on social media platforms, as long as their comments do not include curses, express hatred or advocate actions violating the social order.

She said teachers are also welcome to discuss political topics with students as long as they are related to the syllabus and the information provided is accurate.

"If they have certain topics to discuss with the students, it should be related to the syllabus. Teachers should focus on what the students can learn and whether the process of teaching is appropriate," Choi said.

"It is not about what should or shouldn't be discussed. People like to talk about whether teachers can discuss the June Fourth incident, but the syllabus actually includes such incident."

The minister added that in the past complaints against teachers had taken a long time to process – but from now on, schools would help to deal with cases and pass them on to her bureau.

Speaking on the same programme, Deputy Secretary for Education Teresa Chan said the bureau had processed over 500 complaints against teachers over the past three years, but that only 20 of those were struck off the register, most of those in relation to criminal offences.