Image caption Members of the union went on strike today

Members of a teaching union have gone on strike at Cardigan Secondary School due to concerns about management practices.

NASUWT said it decided to take industrial action because of "adverse management practices" that have created a "climate of fear" in the school.

The union said this is the first of six days industrial action that will be staged during a four week period.

Ceredigion Council has commissioned an independent investigation.

The council said it will also investigate whether a group of teachers and former school teachers have co-ordinated a plan to intimidate, bully and harass members of the senior leadership team.

It said 25 people have been interviewed, which includes members of staff that haven't made any complaints.

Image caption A statement from the union said the decision to strike was taken "with great reluctance"

In response, the NASUWT, described the council's comments as "extraordinary" and an "attempt by the council, it seems, to intimidate and threaten members of staff who have shown the bravery to raise concerns."

The investigation is expected to be concluded by the end of January.

In a statement, teachers belonging to the NASUWT union said the decision to strike was taken with "great reluctance".

"Teachers at the school are hardworking, committed and professional and the strike action is a protest against the gruelling and demanding workload being imposed upon them and the intolerable levels of scrutiny," they said.

Guy Manning left his post as an art teacher in December. He said that there was an unfair amount of work pressure on teachers at the school.

"There's one thing to run a good school and make improvements, and there's flogging your staff until they go, they leave," he said.

BBC Wales has seen a copy of a letter sent by Headteacher, Nicola James, to parents, where she says that the "school will remain open to all pupils on all dates, and meaningful provision will continue to be delivered."

The council says standards at Ysgol Uwchradd Aberteifi have improved greatly over the years, because of the hard work and efforts of staff, governors and pupils.

In a statement, the council added that it has had "a constructive meeting with the NASUWT and appreciate their role as advocates for teaching staff in Ceredigion schools.

"Both the union and the council wish to continue to negotiate and reach a resolution on the matters raised."