A dog found swimming more than 210kms from shore by workers on an oil rig crew in the Gulf of Thailand has been returned safely to land.

Hundreds of workers on Norwegian offshore oil and gas rigs have gone on strike after rejecting a proposed wage deal, leading to the shutdown of one Shell-operated field and helping send Brent crude prices higher.

Officials plan to refloat the oil rig grounded in the Western Isles on Monday night.

Four oil workers have been killed and 16 others injured in a fire on a shallow-water platform in the Gulf of Mexico.