The captain of a U.S. freighter who is being held hostage by Somali pirates nearly escaped Thursday by jumping off a lifeboat, but his captives scooped him back up and are demanding ransom, NBC News reported this morning.

Capt. Richard Phillips’ escape attempt – and subsequent recapture – was witnessed by the U.S. Navy, but the events unfolded too quickly for the American seamen to assist, NBC's Jim Miklaszewski told the TODAY show. The lifeboat, which has run out of fuel, was drifting in the Indian Ocean.

The pirates have vowed to fight any attack by U.S. naval forces stalking them at high sea.

We are not afraid of the Americans," one of the pirates told Reuters by satellite phone on behalf of the gang holding Phillips in the Indian Ocean. "We will defend ourselves if attacked.

Four pirates have been holding Phillips, a former Boston taxi driver, since Wednesday after a foiled bid to hijack the 17,000-ton Maersk Alabama several hundred miles off Somalia.