An EgyptAir flight from Paris to Cairo carrying 66 people disappeared from radar early Thursday morning over the Mediterranean Sea, and Egyptian and Greek officials said it had crashed and a search was underway for debris -- with some pieces possibly spotted.
Egypt's Aviation Minister Sherif Fathy said at a news conference in Cairo that there was a "stronger" likelihood that terrorist action brought the missing plane down than a technical failure.
Egypt's chief prosecutor Nabil Sadek, meanwhile, ordered an "urgent investigation" into the crash. Sadek instructed the National Security Prosecutor to open an "extensive investigation" in the incident.
The director of Greece's Civil Aviation Authority said air traffic controllers were in contact with the pilot of EgyptAir Flight 804, an Airbus A320, as it passed through Greek airspace.
"The pilot was in good spirits and thanked the controller in Greek," the authority said of the last communication with the flight crew, at approximately 2:48 a.m. local time (7:48 p.m. Wednesday, Eastern time), as the jet was cleared to leave Greek airspace.
The authority's director, Constantine Lyzerakos, told private Antenna television that controllers tried to make contact with the pilot again 10 miles before he exited the Greek Flight Information Range (FIR), but the pilot did not respond.
Lyzerakos said controllers continued trying to contact the pilot for about 10 minutes, until 3:39 a.m. Greek time (8:39 p.m. Wednesday, Eastern time) when the plane disappeared from the radar in Egyptian airspace. EgyptAir said it disappeared about 175 miles off Egypt's coast, north of the Mediterranean port city of Alexandria.
A Greek official said the aircraft made sudden "swerves" off its charted course as it plunged and then disappeared from radar.
The jet "turned 90 degrees left and then a 360-degree turn toward the right, dropping from 38,000 to 15,000 feet and then it was lost at about 10,000 feet," Defense Minister Panos Kammenos said at a news conference.
The Reuters news agency cites a Greek defense ministry source as saying authorities were investigating an account from the captain of a merchant ship who reported a "flame in the sky" some 130 nautical miles south of the island of Karpathos.
Greece's Defense Ministry said in a statement that it had sent two military aircraft and a Navy frigate to the area south of Karpathos to join the search, and that two Super Puma helicopters based on the island were also ready to help, according to French news agency AFP.
A Greek military official said an Egyptian search plane had located two orange items believed to be from the missing flight. The official said the items were found 230 miles south-southeast of the island of Crete, but still within the Egyptian air traffic control area. One of the items was oblong, said the official, who spoke on condition of anonymity in accordance with regulations.
A U.S. Navy P-3 Orion surveillance plane from the Sigonella airbase on Sicily was to join the search effort south of Greece, American military officials told CBS News.
Law enforcement sources also told CBS News the FBI would offer assistance to investigators in the crash. CBS News correspondent Jeff Pegues says the FBI is known to have some of the most skilled bomb technicians on the planet, and their dive teams and evidence response teams are also among the best.
The Associated Press contributed to this report.