come on the air, two american families are huddled with the fbi, the search underway for their luchd ones, kidnapped by pirates. The men were last located on this stretch of orben off the coast of... See More
come on the air, two american families are huddled with the fbi, the search underway for their luchd ones, kidnapped by pirates. The men were last located on this stretch of orben off the coast of nigeria. No one has seen the americans now for 48 hours, but tonight, abc news has learned more about who they are. Our chief investigative correspondent brian ross. Reporter: Abc news has confirmed the identities of the two americans on the c retriever, the captain and the chief engineer. Both from southern states. But u.S. Officials have asked us not to broadcast the names of the men, singled out by the pirates because of the sensitivity of the case. We are working closely with our counterparts in the american government and with the nigerians to bring that to a conclusion. Can't say more about it at this point. Reporter: At the same time the nigerian navy says it launched a search and rescue operation in the mangrove swamps where no one pirate and militant groups have camps. U.S. Officials are worried that a nigerian military rescue effort could endanger the americans. How long would it take a pirate who might be drugged to unload an ak-47 on a victim, if the gun is to their head? A second. Two seconds. Reporter: A new gps tracking of the ship on a maritime web site on its final days showed it veered far away from normal route to offshore oil rigs, suggesting the pirates took it to a larger mother ship. Likely rendezvoused with another pirate vessel to steal the fuel off of the vessel and whatever else is on board. Reporter: For the maritime criminals, the two americans on the c retriever were a kind of unexpected bonus. And fbi team is being cents to africa and other agents are working with the families of the two kidnapped americans. But 48 hours since the men were taken, still no known contact with the pirates about what they want to set the men free, diane.
This transcript has been automatically generated and may not be 100% accurate.