Two U.S. residents have been detained in Cuba (search) after a friend reported them missing on their 22-foot boat, but how they reached Cuban waters is unclear.

A man called the Coast Guard (search) on Feb. 5 to report his friends were in trouble at sea.

He "had been in contact with the two individuals by satellite phone. We talked to this friend to try to get a position. He was telling us they were in distress and adrift, basically broken down," Coast Guard Lt. Tony Russell said.

The initial location he offered was near Crooked Island (search) in the Bahamas, but "that just didn't make any sense," Russell said. "The second location given was 18 miles off the coast of Cuba, and then 45 minutes later it was 1,200 yards off the coast of Cuba."

That's when the man said his friends had been stopped by Cuban border guards. The boaters' names have not been released.

Russell had no explanation for the boat trip, but U.S.-registered boats are required to get permits to enter the waters off Cuba.

"What I can comfortably say is the nature of the reporting and the inconsistency of the reports are very consistent with similar cases with similar people we do believe are engaged in smuggling," Russell said.

Small power boats with extra fuel are used by Florida boaters to illegally smuggle people out of Cuba.

"We've seen these reports that there are these two individuals being detained in Cuba," Richard Boucher, a State Department spokesman, said Friday in Washington. "We're still looking into them and trying to ascertain the whereabouts of these individuals and see if there is anything we can do on their behalf."