China's ruling Communist Party has called for greater political instruction for young university teachers, the education ministry has said.

Political education courses are currently mandatory for Chinese youths throughout their schooling, even as adherence to communist ideology has loosened among both officials and the wider public in recent decades.

Party committees overseeing higher education "must attach great importance to ideological and political work among young teachers", said a policy document reported on the education ministry's website on Monday.

The paper "stressed the need to intensify the study of political theory" and "earnestly strengthen ideological education for young teachers", it said.

Teachers' own research should not face restrictions but classroom lectures should be controlled, it added, urging that "words and actions that could harm the national interest or students' healthy development are put to an end".

The paper was issued jointly by party bodies overseeing ideology, human resources and education.

An unnamed official quoted on the ministry website said that "a minority of young teachers' political convictions are hazy, their ideological beliefs are fuzzy.

"Certain teachers' words and actions cannot serve as examples to others," the official said.

The Global Times on Wednesday quoted professors as saying their universities did not require political instruction or monitor teachers in the classroom.

A dean at Xian International Studies University told the newspaper that it trusted young teachers' judgement.