I would not have been the only headteacher on Sunday night wondering how best to talk to our children about the Paris terrorist attacks. We are quite a closed community, bound by our geography. The vast majority of our students are white. We do our very best to provide children with the opportunities to learn about cultures, religions and races they would not otherwise be familiar with.

One thing most headteachers can take for granted is that their staff are united by a moral purpose. We work in schools because we want to invest in children’s futures, educating them to become global citizens. So although I knew full well that when I arrived at school last Monday I would come across children whose opinions about the events in Paris would be at best closeted and misguided, I did not expect it from my staff.

By the end of the day there had been a bust-up in the staffroom about whether Islam was fundamentally a violent religion

During morning briefing some shifted uncomfortably when I explained the clear and consistent message we needed to reinforce: that the refugees from Syria were fleeing from the same people killing Parisians; that to blame all Muslims for the attacks was exactly what the terrorists wanted; that we are a school where hate is not allowed. The vast majority nodded and as I moved around the building later I observed many positive conversations between staff and students. I was so proud to find one of our few Muslim girls spending breaktime with more friends than usual.

It was not all plain sailing. There were comments directed towards a Hindu boy. A small group of children spread a rumour that our town would be bombed next. It all became too much for a couple of vulnerable youngsters and they simply needed to hide in an office and cry.

I did not expect anything untoward from staff. Naivety? A young teacher asked to speak with me, and told me of concerns that an older member of his team had been sharing Britain First posts on Facebook; he found the sentiments racist and offensive. One of the receptionists spoke to her line manager about colleagues saying: “They should let them all sink and die, even the kids”; “Send them back to their own country”; “Shoot to kill” and more. And by the end of the day there had been a bust-up in the staffroom about whether Islam was fundamentally a violent religion.

Emotions were running high, people were saying things they had not thought through. Carefully, I spoke to the offended, and to those who had offended – and tackled them without pointing the figure and shouting “Nasty, racist, xenophobic Islamophobe!” – though at least once I wanted to.

As a headteacher, I expect disagreements over lesson observations and accountability. I never thought I would have to remind staff not to be racist.

I will be doing my best to counter this by talking to staff, debating with them fiercely when I need to. But this feeling in my school concerns me deeply. If you can’t count on teachers to offer a thoughtful and informed reaction in the face of these atrocities, I worry about my country.

•The writer is headteacher of an academy