Coast Guard officials received two apparent distress calls Monday and Tuesday from a location near Little Diamond Island, but weren’t been able to locate any vessels in trouble.

Chris Berry, a civilian search-and-rescue coordinator for the Coast Guard, said the calls were forwarded from 911 operators in Portland. He said the operators received the call, but there was no one on the line and computers that track the source of the calls indicated they came from west of Little Diamond Island.

Berry said the Coast Guard sent out search vessels in response to both calls, but found no vessels in distress. He said the call Monday came in around midday and the Coast Guard sent out a 29-foot response boat to the location, but didn’t find anything after a search lasting about two hours.

Tuesday’s call came in around 8:30 a.m. from the same location, he said, and the Coast Guard sent out a 47-foot boat and, again, found no problems, this time after an hour-long search.

Berry said the phones were apparently in 911 mode, in which, if a phone owner lets a cellphone plan lapse, they can still use the device to call 911 but no phone number information is transmitted, only a geographic location indicating a spot from which the call was made.

He said the location is very specific, so the Coast Guard was able to pinpoint a location for their searches.