- US intelligence believes that ISIS or an affiliated terrorist group may have planted a bomb on the Russian flight that went down in Egypt's Sinai Peninsula on Saturday, a US official told CNN's Barbara Starr.
- The intelligence is not definitive: according to Starr, US officials believe this "most likely was a bomb" but that's "not an absolute conclusion."
- ISIS has a presence in the Sinai Peninsula, the area where the plane went down, and the group has repeatedly claimed responsibility for the plane's destruction. Until now, there had been no statements from any government officials supporting the group's claim.
- The crash, which killed 224 people, would be the deadliest terrorist attack on an aircraft since September 11, 2001.
What the US official says about Metrojet Flight 9268
Earlier today, the UK issued a statement saying it believed the flight "may well have been brought down by an explosive device."
Initially, Russian and Egyptian investigators found no evidence that Metrojet Flight 9268 had been struck by a missile, and independent experts were skeptical that ISIS had the capability to hit it with one.
However, it's plausible that a bomb may have been placed on the plane before takeoff and detonated mid-flight. Reuters, citing Russian officials, reports that the plane likely broke apart at 30,000 feet. CNN had previously reported that a US military satellite detected a "midair heat flash from the Russian airliner before the plane crashed."
Starr's report does not currently say what evidence the US has pointing to ISIS or an affiliate, and emphasizes that the intelligence is tentative.
If this does turn out to be an ISIS attack, this would be a worrying sign. ISIS's military efforts, so far, have principally focused on taking and holding territory in the Middle East rather than executing large-scale transnational terrorist attacks. An attack on a Russian commercial airliner would be a serious escalation on that front.
According an ISIS statement reported on Saturday, the attack was retaliation for Russia's recent intervention in Syria. The attack, the group said, was "in response to Russian airstrikes that killed hundreds of Muslims on Syrian land ... you who kill will be killed."