KUALA LUMPUR, July 20 — Police believe that a homemade bomb thrown into the discipline and counselling room of a school in Kelantan is believed to have been committed by dissatisfied students.

Malay daily Kosmo! reported that investigations have revealed the act was done by three Form Three students apparently unhappy with their discipline teacher.

The incident, which took place at 11am yesterday, resulted in 80 window panes of SMK Penambang's discipline and counselling room being shattered after the bomb was thrown.

One teacher said he was in a nearby building when a loud explosion startled him, followed by billowing smoke from behind the school block.

"When it happened there were six teachers in the discipline and counselling room. Another teacher present said the explosion also resulted in damage to an air-conditioner,” he told reporters.

Meanwhile Kota Baru district police chief ACP Ismail Mat Sidik said plastic remnants of the explosives, made from a modified ball-shaped firework, was discovered at the scene.

"The incident occured on the third floor of Block C. No injuries were reported, and we are still investigating further into the motives of the students,” he said.

It is understood the three students managed to escape after bombing the rooms. The case is being investigated under Section 435 of the Penal Code, for mischief by fire or explosive substance with intent to cause damage.