Township Stories, Traverse Theatre, Edinburgh <!-- none onestar twostar threestar fivestar -->

There's an amusing moment in Township Stories when, spooling back to an earlier point in this web of interconnected tales, characters run busily around in backwards motion, seamlessly resetting the stage.

Another flash of light relief comes in the touching camaraderie between a couple of old mates, just two among many hopeless drunkards drowning their sorrows in a shebeen. But while it's refreshing to have such an excellent and versatile black South African company, playwright and director throwing some hard-hitting punches on the predominantly white, soft-bellied Edinburgh Fringe (then touring extensively throughout England), I just wish the play had contained even a glimmer of positive morality. More than docu-drama, it's not theatre in the sense that you feel better for having seen it, but it is an important and cutting-edge piece of work.

For the main part, this glimpse of life in an anonymous South African township is unremittingly harrowing and hardly a show the country's tourist board will be rushing to promote. It's produced by Lion's Den and, from the piercing screams pre-echoing the arresting opening scene, you feel as though you've entered one. A petrified teenage girl runs gasping round the stage, as if her life depends on it. It does. She doesn't escape her invisible evil tormentor and subsequent rapist and murderer. Hers is the first item of clothing pegged to a washing line crossing overhead. By the end of Township Stories there are 10 pieces of such memorabilia dangling across the stage.

Woven together by Presley Chweneyagae (who starred as the gang leader in Tsotsi), with co-writer and director Paul Grootboom, Township Stories draws together several strands to form the network of a thriller. The result is a dark and disturbing picture of life in an anonymous post-apartheid South African township, evoked in Declan Randall's simple, versatile set. "Life is hard - death is easy," is one child's mantra but, as the play's hard-hitting message makes clear, most of what happens on the journey between the two is desperately unjust and brutal.

The identity of a serial killer, "the G-string Strangler", is baffling the local cops, whose own conduct leaves much to be desired. Suspects are framed and tortured, children are abused by their parents, teenagers fall prey to casual seduction in the vain hope of escaping a rotten home life, and women - treated mostly as mere objects - are regularly beaten. A self-inflicted abortion and a gory killing by a hideously threatening hit man add to the grisly bleakness, pulverising one's emotions. It's a punishing event, not one for the faint-hearted. The misery and hardships of men with little education and women - "sluts" or "bitches" - with no rights, are revealed in tremendously powerful performances. And Grootboom and Chweneyagae allow not the tiniest sliver of hope that life will ever deal a better hand for the people of this dirt-poor community.

Inspired by the structure of P T Anderson's movie Magnolia the play evolves within an effective film-like structure, a clutch of overlapping melodramas leading to a scarcely surprising climax. The fine 16-strong cast, led by Zenzo Ngqobe (who played Butcher in Tsotsi, captures the savage realism of their roles, each layer of Paul Grootboom's well-paced production revealed with the sharpness of a machete. Although the words are spoken mainly in English and some lines are in a local South African dialect, the mix of languages rarely gets in the way of the narrative. The soundtrack, which includes Louis Armstrong, Tracy Chapman and Paul Simon, as well as South African kwaito music, is cunningly deployed as a leitmotif to each scene. Sublime sounds or romantic words paradoxically accompany the most vicious stage business, ending with "It's a Wonderful Life". That, it clearly isn't.

Traverse Theatre until 2 September (0131-228 1404) Details of British tour on www.ukarts.com