A LOUD alarm which sounded across the Milford Haven waterway early on Saturday morning was a malfunction of the Valero Refinery alarm system, it has been confirmed.

Social media was awash with questions and concern after an alarm at the Valero refinery started to sound at about 6.30am.

The alarm continued intermittently until around 7.30am.

Valero spokesperson, Refinery Public Affairs Manager Stephen Thornton, told the Western Telegraph: “At approximately 6:30am on Saturday June 17, the site alarm system malfunctioned causing it to sound a false alarm.

"Refinery personnel completed an initial investigation and repairs were completed. Later the same day the site alarm was successfully tested.

"As ever, the safety and well-being of our employees, contractors and communities remains Valero’s highest priority.”