For those of us conditioned through life to be colour blind — and especially so where theatre is concerned — there is something profoundly shocking about a play like Vivienne Franzmann’s Mogadishu, which is brought to Oxford Playhouse this week in a joint production (director Matthew Dunster) by Manchester’s Royal Exchange and the Lyric Hammersmith.

Watching this startling, utterly riveting drama, concerned with savage life in some schools today — and specifically one in London — we are not expected to disregard the racial background of those involved but instead to comprehend and ponder upon it.

So it is that the programme-cum-script — which could be half the size were all the ‘fs’ and ‘cs’ reduced to this form — tells us directly what all eyes can already see. This is that some characters are “black”, some “white” and one “Asian Muslim”.

Whether the viewer is comfortable with this depends very much on whether she or he is happy with such categorisation and, to an extent, with the stereotyping that is a corollary to it. Personally, I was not.

Some will consider Franzmann, for 12 years a secondary school teacher in London, very brave to have written a first play that tackles head-on one of the major problems of education today.

But since that problem is clearly stated to be, in a nutshell, that young black men are feckless folk who won’t work — certainly true of the three depicted here — I am dismayed that such a clichéed view should be given an airing, however dressed up it is in the language of qualification and concern.

The focus of the drama is a popular liberal teacher Amanda (Jackie Clune) who intervenes to assist bookish young Turk Firat (Michael Karim) when he is attacked in the playground (actually a caged ring in Tom Scutt’s design) by troublesome black kid Jason (the excellent Ryan Calais Cameron). Amanda is knocked to the ground in the incident but urges the harried headmaster Chris (James Barriscale) to take no action. (“I shouldn’t have stood in his way.”) Sensing trouble, though, the cunning Jason himself claims to have been the victim of an attack and of racial abuse by the teacher, using his authority and charisma to persuade his mates to assist in the calumny. Easily brought on board are his intellectually challenged black pals Chuggs (Tendayi Jembere) and Jordan (Hammed Animashaun), the Asian Saif (Farshid Rokey) and white girl Chloe (Tara Hodge). Jason’s black girlfriend Dee (Savannah Gordon- Liburd) is more equivocal, and remains so as the troubling case continues, coming later to involve social services and the police.

Amanda’s principal, really only, allies are her difficult, self-harming daughter Becky (Rosie Wyatt), also a pupil at the school, and her husband (and Becky’s stepfather) Peter (Jason Barnett). The domestic tensions in their household — and the fact that Peter is black — add an extra dimension to the drama. So does the uneasy relationship — in some ways mirroring Becky’s home life — between Jason and his caring, end-of-his-tether dad Ben (Nicholas Beveney).

Though the good intentions of the play can hardly be denied, it remained for me, as I said, an uncomfortable night of theatre.

Until Saturday. 01865 305305 (oxfordplayhouse.com)