WASHINGTON (CNN) -- Pirates in ships are searching for the lifeboat containing four pirates and their hostage -- the captain of a freighter they failed to hijack earlier this week -- according to a U.S. military official with knowledge of the situation. Capt. Richard Phillips of the Maersk Alabama is being held by pirates on a lifeboat off Somalia. The pirates are using ships they have already hijacked and larger ships from which they are launching skiffs, the official said Friday. One of the pirated ships is the German cargo ship Hansa Stavanger, seized April 4 off the coast of Somalia.
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NEW: Shots fired in escape attempt, captain apparently tied up, military officials say
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Pirates using other hijacked ships to look for lifeboat as Navy ships arrive
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Captain's escape attempt viewed as "optimistic sign" of his vitality
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Richard Phillips, captain of a U.S.-flagged cargo ship, is being held by four gunmen
Richard Phillips, the hostage, tried to escape from the pirates Thursday night by jumping out of the lifeboat, a @placeholder official said Friday.