The northern coastline of the United Arab Emirates has been hit by a large oil slick after an oil barge sank off-shore. Around 4,000 tons of crude oil are estimated to have spilt from the ship, which was coming from Iran. As our correspondent in the Gulf, Frank Gardner, reports from Dubai, beaches, desalination plants and marine life are all now at risk from one of the largest local oil slicks in recent years:

The tiny Gulf Emirate of Umm Al Qaiwain in the UAE has borne the brunt of the oil slick, which has washed up on beaches in layers several centimetres thick. But the neighbouring Emirate of Ajman has also been affected, with its desalination plant closed as a precautionary measure.

Ajman's harbour master, Captain Mohammed Miskin, told the BBC that the slick had been surveyed by helicopter on Friday and that the area it covered was vast. Situated close to the busy shipping lanes that pass through the Straits of Hormuz, the coast of the northern Emirates is no stranger to oil pollution but this latest slick is serious enough to have triggered a national effort to limit the damage.

Worst affected are the local fishermen, whose nets have been clogged with oil. But the owner of Umm Al Qaiwain's beach hotel told the local paper, Gulf News, that all 150 of his tourists were confined to their chalets as the beach was also badly polluted.