Flights from an Egyptian airport to the United Kingdom will resume Friday amid speculation on what brought down a Russian airliner last week.
The flights from Sharm el-Sheikh airport, where Metrojet Flight 9268 originated, will resume with new security measures as US and British officials say a bomb likely caused Saturday's crash in Egypt's Sinai Peninsula.
Russian and Egyptian authorities say forensic evidence from the scene will reveal what happened to the doomed jet.
But as flights from the airport resume, passengers will only be allowed to carry hand baggage onto the plane, with other luggage transported separately, the British prime minister's office said in a statement. It didn't explain how passengers would be reunited with their luggage.
Flights from UK not back on
"Outbound flights from the UK to Sharm el-Sheikh remain suspended and the Foreign Office continues to advise against all but essential travel by air to or from Sharm el-Sheikh airport, but we are continuing to work with the Egyptians to get back to normal service as soon as possible," the statement said.
British and Irish officials had announced Wednesday that flights from Sharm el-Sheikh to their countries would be suspended because of concerns about security.
Did someone plant a bomb?
US intelligence assessments suggest someone planted a bomb on the plane before takeoff, multiple US officials said Wednesday, and that someone inside Sharm el-Sheikh airport could have helped.
However, Egyptian Civil Aviation Minister Hossam Kamel said it's too early to make that suggestion.
British Prime Minister David Cameron says it's "more likely than not." US President Barack Obama says "it's certainly possible."
But Russian and Egyptian authorities pushed back Thursday on suggestions that a bomb brought down Metrojet Flight 9268 over Egypt's Sinai Peninsula, saying there's no evidence yet to support that theory.
The debate over what caused Saturday's crash, which killed all 224 people on board, comes as officials say their investigation is far from finished.
US officials have told CNN that intelligence suggests that ISIS or its affiliates planted a bomb on the Russian plane.
How? One US official told CNN that "specificity" in chatter surrounding the crash of the Russian jet drew the attention of the U.S. intelligence community. The official says "the specific nature of the discussion" that officials monitored made them take notice.
The intelligence also suggests someone at the Sharm el-Sheikh airport helped get a bomb onto the plane, another US official said.
Intelligence isn't definitive
But the intelligence isn't definitive, Obama said in an interview Thursday with Seattle radio station KIRO.
"We're going to spend a lot of time just making sure our own investigators and own intelligence community find out what's going on before we make any definitive pronouncements," he said. "But it's certainly possible that there was a bomb on board."
Cameron said Thursday that he couldn't confirm "with certainty" why the Russian commercial jet crashed. Still, he said, the possibility was enough of a reason to keep British citizens from flying back for several days this week from Sharm el-Sheikh, a popular tourist destination in Egypt, until safety measures at the resort's airport could be bolstered.
Egypt is leading the crash investigation. Russia, France, Germany and Ireland also have investigators on the ground. But the United States and the United Kingdom aren't part of the investigative team combing over forensic evidence from the scene.
Egyptian Civil Aviation Minister Hossam Kamel said investigators have found no evidence to support the theory that a bomb caused the plane to crash.
Neither the United States nor the United Kingdom has shared intelligence about a possible bomb with Egyptian authorities, Egyptian officials said.
Russian President Vladimir Putin said data from the official investigation should form the basis for assessments of what caused the crash, the Kremlin said in a statement.
Did ISIS down pane?
The signs pointing to ISIS, another US official said, are partially based on monitoring of the terrorist group's internal messages. Those messages are separate from public ISIS claims of responsibility, the official said.
In an audio message from ISIS' Sinai branch that was posted on terror-related social media accounts Wednesday, the organization adamantly insisted that it brought down the flight.
Typically, ISIS is quick to trumpet how and who carried out any attacks for purposes of praise and propaganda. To some, the fact that ISIS hasn't provided details in this case raises doubt about the group's repeated claims of responsibility.
Officials in Egypt and Russia have said there's no evidence to support ISIS' claims.
Funerals for the Russia victims on the doomed plane started Thursday. Others will be held Friday.