THE Valero Pembroke Refinery is among the sites hit by a major power failure across the UK this evening (Friday), it is understood.

Large flares and black smoke have been seen coming from the refinery's stacks.

People living in the Milford Haven area have also reported foul smells they believed to be coming from the site.

The major power cut has hit airports and rail networks across the UK.

Blackouts have been reported across the South East, Midlands, South West, North East and Wales.

UK Power Networks said the issue was caused by a "failure on National Grid's network".

National Grid said it was caused by issues with two power generators but the problem was now resolved.

A spokesman for Valero told the Western Telegraph: "We do not comment on operational matters" and declined to comment further.