People in Pembrokeshire who hear sirens in the vicinity of Valero Energy at Pembroke this Thursday, May 16, need not be alarmed that an emergency has broken out at the refinery.

This is because the facility will be holding an emergency response drill,

People can expect to see emergency services in action and hear sirens as part of the simulation.

A spokesman for Valero has asked people to spread the word about the drill so that everyone around the Pembroke area can be kept informed and stay calm.

They added: "There's no need for concern, it's only a practice exercise."