A witness, Mark Ashbridge, took this picture of the small blast in Belfast city centre.
It appears people had been pushed back before the explosion occurred.
Mark says "the glow is the result" of the blast:
No injuries have been reported.
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As many as 2,000 British holidaymakers could be among those stuck at emergency accommodation as snow causes chaos for holidaymakers.
Tributes have beenb paid to Harry Potter and Outnumbered actor David Ryall who died on Christmas Day aged 79.
We are set to enjoy some sunshine after all that ice, snow and frost - albeit with temperatures still low.