A US infra-red satellite reportedly detected a "heat flash" aboard the Russian passenger jet that crashed in Egypt's Sinai Peninsula on Saturday, a US official said on Tuesday.
The official said the US intelligence community believes the heat wave could have been the end product of an explosion within the plane, possibly that of a fuel tank or a bomb. The US provided satellite imagery also ruled out a surface-to-air missile attack, debunking DAESH's claim that it downed the plane with such a missile.
DAESH's affiliate in Egypt, Wilayet Sinai (Sinai Province), claimed that it took down the Russian airliner on Saturday, killing all on board.
"The speculation that this plane was brought down by a missile is off the table," the official told NBC News.
James Clapper, the US Director of National Intelligence, also said on Monday that he knew of no direct evidence that terrorism was the cause of the Russian airplane crash in the Sinai on Saturday.
The Russian airline tragedy claimed the lives of 224 passengers and crew members, 17 of whom were children. Approximately 144 bodies were delivered home to Saint Petersburg on Monday.
Clapper spoke to a Washington defence conference and said it was 'unlikely' that DAESH has the capacity to carry out such an attack, but added, "I wouldn't rule it out."
"We don't have any direct evidence of any terrorist involvement yet," he said.
Cairo and Moscow have strongly dismissed DAESH’s claim that it targeted the Russian passenger jet that took off from the resort city of Sharm al Sheikh to travel to the second largest Russian city of Saint Petersburg.
"ISIL [DAESH] has claimed responsibility," Clapper said, "but we really don't know" if it is involved. “Once black-box information has been analyzed, perhaps we will know more," he added.
Nicholas Rasmussen, the director of the National Counterterrorism Center, also commented on the incident, stressing that it is too early to link DAESH to the airline catastrophe.
Rasmussen told the defence conference that the investigation is still ongoing, but "at this point, we've got nothing in intelligence to corroborate a nexus to terrorism."
"We've seen no reports that would support that," State Department spokeswoman Elizabeth Trudeau said of the notion that the plane was downed by DAESH.
‘Missiles that down planes are state-owned’
Agence France Presse (AFP) quoted a US defense official as saying missiles strong enough to bring passenger planes down are usually owned by "state actors." The anonymous official told the agency he was skeptical over the matter as a whole.
According to the Russian airliner, Metrojet, "an external influence" is the only reasonable explanation for why the passenger jet crashed in the Egyptian Sinai peninsula on Saturday, an executive from the airline said on Monday, reiterating that planes don't just break apart in midair and the accident wasn’t the end result of a human error.
"We exclude technical problems and reject human error," Alexander Smirnov, an official at the airline, told a news conference in Moscow, as he discussed possible causes of the crash. "The plane was in excellent condition," he added.
Russian investigators in Cairo argued that the plane may have broken up in mid-air, yet stressed the fact that it is still too early to draw conclusions from this.
The crashed Airbus A321-200 was 18 years old and previously had an accident involving its tail section, but the airline officials said that full-scale repairs to the plane had been made successfully. Given that, the officials said there was no reason to think that the tail accident had anything to do with Saturday's crash. There was also no emergency call from the plane's pilots to services on the ground during the flight.