ESSEX Police took to social media to reassure members of the public after a controlled explosion was carried out at the force's headquarters.

A message posted on the Force Control Room's Twitter account yesterday said: "If you are in Chelmsford and have just heard a loud bang, that was us detonating some explosives at our headquarters - please don't panic!"

According to witnesses, the blast from the Sandford Road site could be heard two miles away.

An Essex Police spokesman said: "Essex Police, working with 11 Explosive Ordnance Disposal Regiment, Royal Logistic Corps, conducted a controlled explosion at our headquarters in Chelmsford yesterday.

"Essex Police required assistance from 11 EOD to make safe and dispose of a live, black powder firearm. The firearm was legitimately held and handed over to us."