SIGNIFICANT damage was caused to a building near the city centre after household rubbish was set alight on Saturday evening.
Witnesses said they saw a man dressed in dark clothing running away from the fire in the direction of Park Street, Worcester.
Fire crews were called to a substantial fire at the rear of a block of flats in Park Street at about 10.30pm.
The blaze was within a small plot of land off Lock Street where it is believed someone had ignited household rubbish that started the fire.
The fire caused significant damage to an adjoining property.
Police are keen to speak to the man and urge anyone who may have more information or saw the man to call the non-emergency police number 101, quoting incident 740 of August 16.
Alternatively, information can be given anonymously to Crimestoppers at www.crimestoppers-uk.org or by calling 0800 555 111