An investigation has been launched into the cause of a blaze at an oil refinery in Pembrokeshire, west Wales.

Work is now back to normal following the fire which broke out on Tuesday night at the Texaco plant in Pembroke Dock which produces 200,000 barrels of oil a day.

Eyewitnesses reported seeing smoke rising nearly 1,000ft into the air and several local fire crews were called in to tackle the blaze.

The fire started from a hydrogen leak in one of the refinery's units, but it is not yet known what caused the hydrogen to ignite.

An investigation is underway.

A spokesman for the refinery said a fire was reported at the site's Unifiner Process Unit at 2127BST on Tuesday.

The Texaco plant's own fire crew attended the scene and brought the fire under control.

Water jets were sprayed over the affected area, where there is believed to have been a hydrogen leak.

A spokesman said it was too early to assess the extent of the damage, but he thought it was minimal.

There had earlier been eyewitness reports of smoke reaching up to 500ft high at the site, moving in the direction of Pembroke Dock eight miles away.

Eight fire engines from the local fire station were also mobilised, but were placed on standby at the plant.