A huge steel dome was placed Saturday over a gushing wellhead on the floor of the Gulf of Mexico in a bid to stop the leak of oil, the US tv news network CNN reported, according to dpa. The four-storey oil-containment dome, weighing some 100 tons, is to try to cap the oil leaking from the sunken Deepwater Horizon rig and then funnel the oil to connecting pipes leading to the surface. On Friday, operator British Petroleum (BP) said the capping technique had never been tried at such a depth - 5,000 feet (almost 1,600 metres) - and there were no guarantees that it would work. If all goes well, BP hoped to begin sucking the first crude oil through the upside-down funnel and into a waiting tanker on the surface by early next week. -- SPA