Education professionals on Wednesday called on officials to revise guidelines for school flag-raising ceremonies to offer clarity on how pupils who fail to respect national emblems should be penalised.

The calls follow a decision by a school in Tsuen Wan to suspend 14 pupils for three days after they failed to turn up for the raising of the national flag.

Speaking on RTHK's Hong Kong Today programme, Mervyn Cheung, the chairman of the Hong Kong Education Policy Concern Organisation, said the punishment imposed by St Francis Xavier's School was "drastic", and said suspending pupils should be a last resort.

"I think the EDB (Education Bureau) should consider revising the circular that it issued last year and be more specific with the penalties for non-compliance," he told RTHK's Ben Tse.

He said that the severity of any punishment could be based on factors such as whether the pupils were being negligent or whether their actions were deliberate.

Lawmaker Tang Fei, who is also a secondary school principal, echoed Cheung's call for clarity on the matter of penalties.

Speaking on another RTHK programme, Tang said this could help schools avoid giving the impression that class suspensions may be too harsh.

He defended the decision by St Francis Xavier's School, saying that it had followed the necessary protocols.

"It had stated clearly and taught its students on what should be done during a flag-raising ceremony," said Tang, adding that the school had informed the pupils' parents and the Education Bureau in accordance with guidelines after the incident.

He said that schools should not be left to decide on what penalties to hand out, pointing out that there are laws governing the treatment of violations linked to the national flag, emblem and anthem.

The Education Bureau said on Monday that it was seeking a report on the incident from the school. It said there are clear rules governing etiquette during the national anthem and flag-raising ceremony.