'Heat detected' around Russian plane before it crashed
US satellite systems detected heat around a Russian passenger plane before it crashed in Egypt and killed all 224 people aboard, two US officials have said.
One of the officials said they ruled out a missile striking the Metrojet Airbus A321-200 because neither a launch nor an engine burn had been detected.
The infrared activity that was detected could mean many things, including a bomb or that an engine on the plane exploded because of a malfunction.
Aviation analyst Paul Beaver said the heat picked up by the satellite "indicates that there was a catastrophic explosion or disintegration" of the plane, but does not reveal what caused it.
"It doesn't tell us if it was a bomb... or if somebody had a fight in the airplane with a gun - there is a whole raft of things that could happen in this regard," he said.
He said it also could indicate a fuel tank or engine exploding, although "engines are designed so that if something malfunctions or breaks off it is contained within the engine".
Some aviation experts earlier suggested a bomb was the most likely cause of Saturday's crash, while some others pointed at a 2001 incident in which the jet damaged its tail during landing.
In Egypt, an international team of experts prepared to analyse the plane's flight data and cockpit voice recorders.
The joint investigation committee, which includes Egyptian and Russian experts as well as representatives from Ireland, where the plane was registered, will conclude its last field inspection at the crash site by the end of the day and start working on the black boxes, said Egyptian civil aviation minister Hossam Kamal.
Mr Kamal says it "will take some time" to produce the final report and that the committee "has all the tools and experts to deal with the investigation".
Russian transport minister Maxim Sokolov said that Russian experts already had conducted a preliminary inspection of the two "black boxes" and had seen information from Egypt's flight control radars, but he would not mention any further details.
The Metrojet flight was en route from Egypt's Red Sea resort of Sharm el-Sheikh to St Petersburg when it crashed in the Sinai Peninsula after breaking up at high altitude, Russian aviation officials said. All of the victims, except for four Ukrainians and one Belarusian citizen, were Russian holiday-makers flying home.
Islamic State (IS) militants said shortly after the crash that they had "brought down" the Russian plane because of Moscow's recent military intervention in Syria against the extremist group.
But the group did not provide any evidence to back up its claim, and militants in northern Sinai have not shot down any commercial airliners or fighter jets.
Egyptian president Abdel-Fattah el-Sissi insisted that the security situation in the Sinai Peninsula is under "full control" and that claims by IS that it downed the plane were "propaganda" aimed at damaging the country's image.
In an interview with the BBC, Mr el-Sissi also reiterated his assertion that the cause of the crash may not be known for months and that, until then, there should be no speculation about it.
Alexei Smirnov, of the Russian emergency situations ministry, said 140 bodies and more than 100 body parts were delivered to St Petersburg on two government planes on Monday and Tuesday. Families on Tuesday identified the first 10 victims.
Mourners continued to come to St Petersburg's Pulkovo airport to lay flowers, toys and other tributes to the dead. On the outskirts of town, tearful families of the victims left a crematorium where the identification procedures are taking place.
Alexander Agafonov, head of the Russian rescue mission in Egypt, said in a televised conference with other officials that searchers have not found a single additional body on Tuesday after combing a 28 square-kilometre (10.8 square-mile) area. Emergency situations minister Vladimir Puchkov said the site "should be studied centimetre by centimetre".
"If you need to sift through the sand where the remains or pieces of the fuselage could be, do it," he said.