MONROVIA—As many as 17 people were missing from a cargo ship that sank off the coast of Liberia over the weekend despite being barred from setting sail, the Maritime Commissioner said. The Liberian-registered Niko Ivanka left the capital Monrovia on Saturday for a port in the West African country’s south, despite being under a detention order for failing to meet basic safety requirements. The vessel sent out a distress signal that afternoon, notifying the coastguard that it had taken on water. By the time authorities arrived, it had already partially sunk. Eighteen people were on the ship’s manifest, 11 of whom had been rescued during a 36-hour search, commissioner Eugene Nagbe told reporters on Monday. But those rescued said that there were in fact about 28 people on board, leaving 17 missing. “For now, our concern is a search and rescue mission,” Nagbe said. “My focus is the lives of …