A hijacked Singapore-registered oil tanker has been recovered and escorted to Abidjan port in Ivory Coast, five days after it was captured by pirates in the Gulf of Guinea, the Ivorian military said. On Tuesday, Singapore's port authority said the tanker had been boarded by "unidentified persons" about 300 nautical miles (555 km) off the Ivory Coast with 20 crew of various nationalities aboard. A search operation by Ivory Coast's navy backed by a French navy aircraft located the vessel on Saturday, Ivorian Armed Forces Chief of Staff Lassina Doumbia said in a statement. "As for the crew, they are safe and…