European and U.S. satellites captured emergency distress signals from EgyptAir Flight 804 minutes after it fell off radar May 19, according to the National Oceanic and Atmospheric Administration.

A device known as an emergency locator transmitter, or ELT, began radioing an automatic distress message at 2:36 a.m. local time, Lt. Jason Wilson, an operations support officer at NOAA, said in an email.

Five satellites relayed signals from the beacon to a ground station in Cyprus, according to Wilson and a document prepared by the French government.

The satellites provided a location in the Mediterranean Sea of a probable crash site that is accurate to within 3.1 miles.

The information, which confirms an earlier report on Egypt's state-owned Ahram Gate website, will assist the search for wreckage beneath the sea, including the Airbus A320's two crash-proof recorders.

The plane went down on a Paris-to-Cairo flight with 66 people aboard.

A U.S. ground station in Maryland also was alerted that satellites had “received two bursts from the beacon, but was unable to make a location,” Wilson said in an email.

An Airbus official said he was unaware of any ELT received or given to the Egyptians.

Airliners flying international routes are required to carry ELTs, which are designed to send a signal to satellite networks if a plane crashes, alerting authorities of the accident and providing the location.

The emergency signal came about six minutes after the plane stopped transmitting its location to radar at 2:29:33 a.m., according to the flight tracking website FlightRadar24.

Investigators haven't been able to say what brought down the flight.

The plane transmitted a series of seven emergency messages indicating smoke had been detected in two locations and noting unspecified problems with cockpit windows and flight computers.

The emergency beacon is separate from the so-called pingers on the plane's black box recorders. The pingers are designed to operate underwater so that investigators can locate the wreckage.

The ELT functions only after a crash and cannot transmit underwater.

A French naval oceanographic research ship, Laplace, carrying a long-range acoustic system able to detect signals from the black box, is headed to the crash site, France's air accident investigation agency, the BEA, said in a statement.

The ship left Corsica on Thursday and was due to reach the crash area sometime Sunday or Monday, it said.

Ships and planes from Egypt, Greece, France, the United States and other nations have been searching the Mediterranean north of the Egyptian port of Alexandria for the jet's voice and flight data recorders, as well as more bodies and parts of the aircraft.

Small pieces of the wreckage and human remains have been recovered while the bulk of the plane and the bodies of the passengers are thought to be deep under the sea.

A Cairo forensic team has received the human remains and is carrying out DNA tests to identify the victims.

Egypt's Civil Aviation Minister Sherif Fathi has said he thinks terrorism is a more likely explanation than equipment failure or some other catastrophic event.

But no hard evidence has emerged on the cause, and no militant group has claimed to have downed the jet.

Earlier, leaked flight data indicated a sensor detected smoke in a lavatory and a fault in two of the plane's cockpit windows in the final moments of the flight.

Associated Press contributed.