AT least seven people are missing after a cargo ship that had been barred from sailing sank off the coast of Liberia, the country's Maritime Commissioner said on Sunday. The Liberian-registered Niko Ivanka left the capital Monrovia on Saturday morning for a port in the country's south, despite being under a Liberia Maritime Authority detention order for failing to meet basic safety requirements. The vessel sent out a distress signal that afternoon notifying the coast guard that it had taken on water, Maritime Commissioner Eugene Nagbe told a news conference. By the time authorities arrived, it had already partially sunk.…