The communists were once again trying to infiltrate Chinese-medium schools to stir up trouble, Education Minister Ong Pang Boon warned this week in 1965.

He also disclosed that eight students had been expelled from The Chinese High School in Bukit Timah Road for their alleged political involvement. This followed their conviction in court for involvement in the 1965 May Day demonstrations held by left-wing unions.

Mr Ong said the expelled students tried to mobilise support from other students for their reinstatement but did not succeed. They even tried to pressure the principal by using abusive language, he added.

Mr Ong also cited an incident at Peng Ghee Middle School in Changi Road, where a student tried to stir up protests after the school decided to discontinue its secondary department because of a lack of facilities.

"The pattern of actions of these students are typically communistic," he said.

"These recent incidents have indicated that the pro-communist elements are stepping up instigation at these schools," he said.

The Government was keeping a close watch, he added.