BEIJING, April 19 (Xinhua) -- China will tighten supervision of education programs jointly operated by Chinese and foreign colleges to ensure that students get quality teaching, the Ministry of Education said here Thursday.

The ministry said on its official website that a recent investigation discovered a series of irregular operations by joint educational institutions, some of which had triggered "mass incidents".

Citing examples, the ministry said some institutions attracted many students with bold advertisements, but failed to deliver high-quality teaching.

Others, which promised to send students study abroad, failed to do so or did not grant students diplomas after they completed their studies.

Such cases, in which students often paid over hefty tuition fees, seriously damaged the interests of students and their families and generated bitter complaints, the ministry said.

The ministry said it will not approve new Sino-foreign joint programs on higher occupational education until 2009. Applications for new joint programs on postgraduate education will be very carefully scrutinized.

The ministry said it has asked provincial educational departments to carry out thorough investigations of current joint educational programs and clean up irregular operations as soon as possible.

It also said it is working on an evaluation and sanction mechanism for joint educational institutions. But no details were given.