AN INVESTIGATION in underway to find out the 'root cause' following an 'explosion' at an Anglesey powder plant.

Two men made their own way to hospital following an incident on Saturday evening, on August 10, at the AMG Alpoco plant in Holyhead.

Residents - from miles away - reported here a 'loud bang' and saw a plume of smoke.

A spokesperson from AMG Alpoco UK Limited, said: "An incident occurred in one of our manufacturing units in Anglesey at 6pm on Saturday affecting part of the plant.

"The situation was quickly brought under control and we can report that the plant safety protocols functioned exactly as designed in the event of such an incident.

"Emergency services attended the site promptly to assist.

"No injuries were sustained to any employee or site visitor and there has been no adverse environment impact as a result of the incident.

"An immediate internal investigation is currently in progress to identify the root cause. The unaffected parts of the plant remain in full operation.

"The Health and Safety executive have been duly notified."

Four fire crews - two from Holyhead, one from Amlwch and one from Bangor - were sent to the industrial works on London Road on Saturday.

A spokesperson from North Wales Fire and Rescue said: "All persons at the works were safely accounted for as fire crews attended to a fire which was confined to a hopper.

"There were no casualties requiring treatment at the scene, however two men have since made their own way to hospital with minor injuries."

Many residents took to Facebook with their concerns after hearing the 'loud bang'.

One user wrote: "Felt it at RAF Valley. Thought the house was gonna collapse. Sooo scary."

Another posted: "Massive plume of smoke then big fireball and explosion."