LONDON: Britain said on Wednesday that the Russian plane that crashed in Egypt this week after taking off from the resort of Sharm El-Sheikh might have been brought down by an explosive device.

“While the investigation is still ongoing we cannot say categorically why the Russian jet crashed,” Prime Minister David Cameron’s office said in a statement.

“But as more information has come to light we have become concerned that the plane may well have been brought down by an explosive device,” it added.

As a precautionary measure, the government has decided that flights due to leave Sharm for Britain will be delayed to allow time for a team of UK aviation experts, currently traveling to Sharm, to make an assessment of the security arrangements in place at the airport.

Investigators have extracted and validated the contents of the flight data recorder, one of two so-called black boxes recovered, Egypt’s Civil Aviation Ministry said on Wednesday.

Meanwhile, Daesh insisted it brought down the plane, providing no new details but challenging skeptics to prove otherwise. In an audio statement posted on social media sites on Wednesday, Daesh said it would announce the details of the alleged attack when it chooses.