Parkview School Birmingham
Park View School was one of the educational institutions put in special measuresGetty

Dead animals left in playgrounds or hung on school gates were part of a new extremist campaign to intimidate teachers in the wake of the Birmingham "Trojan Horse" plot, it has been claimed.

The horror tactics, including death threats, have been witnessed in at least three schools in the UK, the National Association of Head Teachers' conference heard on 3 May.

The Trojan Horse scandal involved 21 schools in Birmingham being inspected by Ofsted after there were allegations of extreme Muslims wanting to take control of schools.

Five were placed in special measures after pledging to convert pupils and staff to Islam. These were Golden Hillock School, Nansen Primary School, Park View School – all run by the Park View Educational Trust – Oldknow Academy and Saltley School.

A leaked document claimed dirty tricks were being used to oust non-Muslim staff in the Trojan Horse operation. Delegates complained governors involved in the alleged plot had still not been investigated or banned and there were calls for a database of governors who had been thrown out of office never to be allowed back into education.

Speaking at the conference, Sarah Hewitt-Clarkson from the city's Anderton Park School, said: "Trojan Horse has not gone away. Those of us who were involved, we knew it was the tip of the iceberg. We still have dead animals hung on the gates of schools, dismembered cats on playgrounds."

She warned of other issues such as the backlash schools faced if they are in favour of teaching on sexual equality.

Hewitt-Clarkson said: "We have petitions outside schools objecting to teachers teaching against homophobia. We have death threats on Facebook, for example, towards me 'or any headteacher who teaches my children it's all right to be gay will be at the end of my shotgun'."