Maritime officials in East Africa said they have received reports that at least two previously hijacked ships with dozens of hostages aboard have moved into the area where four pirates are holding an American sea captain captive in a lifeboat.  The lifeboat is floating adrift and being monitored by an American warship nearby.

East Africa maritime sources told VOA that a German container vessel that pirates captured by with 24 crew members last Saturday has been moved north, near the location of Wednesday's attempted hijacking of a U.S.-flagged container ship.  

The Maersk Alabama was seized by four armed hijackers about 440 kilometers southeast of Eyl, a coastal pirate town in the semi-autonomous region of Puntland.   But the hijackers lost control of the ship after the Alabama's 20 American crew members overpowered them.

The pirates then escaped with a covered lifeboat, taking the captain of the vessel hostage.

U.S. news reports early Friday quoting an unnamed Defense Department official said the captain tried to escape from the pirates during the night, but was recaptured after trying to swim away.  

There is speculation that the previously hijacked ships are being sent to the area to serve as shields for the small, enclosed lifeboat that now holds the four Somali pirates and their American captive, Capt. Richard Phillips.  The boat is currently floating adrift after running out of fuel on Thursday.  It is being closely monitored by a U.S. Navy destroyer anchored within view of the lifeboat.   Other U.S. navy vessels are also reported to be heading to the area.

The director of the Kenya-based East Africa Seafarers Association, Andrew Mwangura, said a Taiwan fishing trawler captured near the Seychelles on Monday with 29 men aboard is also believed to be in the area.

Mwangura said he does not believe the pirates intend to mount a rescue operation, but will use the hijacked vessels as mother ships in the hunt for new targets.   He said calm seas and light winds in the area have created ideal conditions for pirates.

"It is good for them.  And during night time, there is moonlight.  So, all of this is good for the pirates.  They can go as far as they can and they can attack other ships," he said.

Pirates generally use mother ships to tow small skiffs far off the coast.  The skiffs, each holding three to five pirates, then chase down large, slow-moving vessels in the high seas.   

In this way, pirates attacked more than 130 ships last year and captured more than 40, earning them millions of dollars in ransom.  At least 17 ships and more than 250 crew members are still being held.

The attempted hijacking on the Maersk Alabama was the first attack by Somali pirates on a U.S.-flagged ship.  The ship, carrying food aid, has set sail for its original destination of Mombasa, Kenya.  Port officials there say they are expecting its arrival on Saturday.