Dozens of schoolchildren were injured when the wooden floor of an old classroom collapsed in Thailand.

The students were holding an English quiz at the Phanatpittayakarn School in Chonburi province when the floor gave way, plunging into a pool of dirty water 10ft below on November 9 afternoon.

Teachers pulled up the shocked pupils, most of whom had sustained minor scrapes. Two youngsters who suffered back pain from the fall were taken to the Phanatnikhom Hospital for further treatment.

A 13-year-old student said the floor near the chalkboard had collapsed in the middle of the school activity and caused some 30 children to fall.

School director Prayoch Keeratipakorn said he had previously ordered repairs on some of the 47-year-old school's facilities when he assumed office. However, he said the classroom in question had been left untouched as the floorboards did not appear damaged.

He added: 'The floor must have collapsed when the students rushed to the front to answer questions. Most of them were only bruised, but a few were taken to the hospital.

'We were already planning to conduct repairs on old classrooms during the school break before the incident occurred.'

The teacher said that the school has apologised to the children's parents for the accident.

Meanwhile, the damaged sections of the school have been cordoned off for repairs. Students were relocated to other parts of the building for their lessons, Prayoch said.