Eyewitnesses have told ITV News Central a number of loud explosions could be heard from the fire at G&P batteries in Darlaston, Walsall.
50 firefighters are currently tackling the blaze on Willenhall Road.
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A dry, bright and sunny start to the Bank Holiday weekend for most.
A dry bright and sunny start for most on Saturday. Some scattered showers will develop inland through the late morning.
A cold and frosty start to Saturday, though with some sunny spells. Showers then breaking out by afternoon.