City schools under the Central Board of Secondary Education (CBSE) beware — big daddy is watching.

A large number of CBSE schools are not following a number of important rules introduced almost four years ago, board chairman Ashoke Ganguly observed on Thursday during a trip into town to unveil Indus Valley World School off the Bypass.

“We are working on a system by which we will be able to identify schools violating our rules. The board will take stern action against errant schools and if necessary their affiliation will be taken away,” warned Ganguly, after meeting principals of more than 40 city-based CBSE schools.

According to the board chairman, many schools are detaining children studying in classes I to V despite the system being abolished more than three years ago.

Nearly 50 per cent of schools are not following the board’s instructions regarding mathematics laboratories to help students fight maths phobia.

There are schools which are still assessing students through the one or two-shot examination system instead of a continuous comprehensive evaluation procedure. Children studying in classes I and II are still being given homework flouting the board’s rulebook.

The principals of some schools later said that ideally they too would like to follow the CBSE rulebook but it was often not practical to do so. “We have a reputation built on the bedrock of outstanding results. If all the policies are adopted at once, performance may suffer. If the grades drop, the guardians would be the first ones to blame the school,” argued a principal on condition of anonymity, adding that many steps are dictated by “competition”.

But Ganguly insisted that many policies adopted by the board to improve performance while reducing stress among students have been violated. “The negligence on the part of schools is putting students under greater mental pressure. The schools will be held responsible if a child takes a drastic step,” he warned.