Sir Philip Pullman's old Harlech school in special measures

Ysgol Ardudwy was rocked by the resignation of its head teacher in September

The former secondary school of writer Sir Philip Pullman has been put into special measures.

Inspectors from Estyn say Ysgol Ardudwy in Harlech needs "urgent improvements" after standards and leadership were found to be "unsatisfactory".

A report said the school has faced a "challenging period" after the head and chair of governors quit in September.

Gwynedd Council said it accepted the need to improve the school but claimed there had been "positive changes".

Head teacher Tudur Williams had suddenly quit after 28 years, saying in a letter to governors and parents that "the time was right to leave".

Pupils had to take lessons in a local theatre after the school was hit by Storm Emma

Earlier in the year, the school was closed for nine weeks after being badly damaged by Storm Emma in March.

Inspectors who visited the school in December said they were satisfied that acting head teacher Aled Williams had a "clear vision" for the school, according to the Local Democracy Reporting Service.

But since he was the only full-time member of the senior management team, it was felt that leadership at all levels had "not succeeded in raising and maintaining high standards or improving the quality of teaching".

Ysgol Ardudwy had been performing significantly worse than similar schools in core subjects such as Welsh, English and maths over the past three years, the report added.

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Gareth Thomas, Gwynedd Council's cabinet member for education, said he welcomed the "positive changes" that had already been implemented at Ysgol Ardudwy over recent months.

"We will continue to work with the acting head teacher and the school's staff on the work of continuing with the improvement process," he added.

Sir Philip Pullman, award-winning author of His Dark Materials, attended Ysgol Ardudwy after his family moved to the area in the 1950s, when his stepfather was posted to RAF Llanbedr.