This poem takes place during the siege of Sarajevo, a terrible and bloody war that ran from 1992-1996. (See the Context section for more on the complex history of this war.) The speaker—who seems to be an outside observer—opens the poem with a description of the lived daily reality of regular Sarajevans, those people who are just trying to survive from day to day and aren't fighting in the conflict itself.
Lines 1 to 6 act like a kind of report from Sarajevo, telling the reader what life during the siege was actually like. (And indeed, the poet, Tony Harrison, was sent to Sarajevo on assignment by a newspaper.) The details are observational and devoid of any flowery poeticism—this is just a plain description of daily reality.
Life under siege is predictably terrible. Getting the resources most people in peacetime take for granted (fuel, food, and clean water, for instance) all become struggles: Sarajevans risk their lives just to refill their "canisters of gas" or to collect "precious meagre grams" of bread to help them survive.
The poem's first stanza is mostly one long, heavily enjambed sentence—an effect that captures the Sarajevans' tension, restlessness, and exhaustion as they try to get through the day. The poem's rhyming couplets also create a quick and nervous pace, making the poem feel like a quickly sketched report from the heart of the action.
There is also a strange sense of routine at work here. This speaks to the way that wartime life becomes normalized. Determined to survive, people in wartime find a weird rhythm and kind of get used to the experience, even if that experience is tragic, unjust, and absurd.
For instance, the Sarajevans "wheel home" their refilled gas canisters "in prams" (or baby carriages) like grotesque babies: the prams are repurposed for an environment that can't really support regular family life. And they queue like shoppers—but instead of purchasing the goods they want, they take whatever "meagre grams / of bread" they can get.
Bread will play a symbolic role in this poem: it's a food so commonplace that it should symbolize everyday life and the communal experience of eating (breaking bread) together. Here it's a symbol of how little the Sarajevans possess, and later in the poem it reappears to devastating effect. Keep an eye out for it.