The British government said Wednesday that it had suspended flights from the Egyptian resort city of Sharm el-Sheikh over concerns that a Russian jet that crashed in the Sinai Peninsula on Saturday “may well have been brought down by an explosive device,” reports Washington Post.

The statement by 10 Downing Street said the cause of the crash remained under investigation, and that British aviation experts were en route to Sharm el-Sheikh “to make an assessment of the security arrangements in place at the airport and to identify whether any further action is required.”

The statement said Britain’s senior security officials would meet Wednesday evening to further discuss what a spokesman described as “a precautionary step.”

The British government said it would release more details following that meeting, and that it expected the review of airport security arrangements to be completed by Wednesday night.

Britain said it had deployed additional consular staff to the Sharm el-Sheikh airport to advise and assist British tourists.

The suspension of flights came just a day before British Prime Minister David Cameron is due to host Egyptian President Abdel Fatah el-Sisi in London. The statement from 10 Downing Street on Wednesday said that Cameron and Sisi had spoken by phone on Tuesday evening to discuss security at the airport in Sharm el-Sheikh.

“While the investigation is still ongoing we cannot say categorically why the Russian jet crashed,” Downing Street said in its 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.”

A spokesperson for Cameron said the prime minister and Sisi had discussed “the need for security measures to be enhanced out of the airport.”

The spokesperson, who declined to be named under the British government’s customary rules of anonymity, would not comment on whether British allies such as the United States had been consulted on the decision to suspend flights.

Britain has not been directly involved in the investigation into why the plane crashed. The spokesperson would not comment on what information had triggered Wednesday’s suspension.

Egypt’s civil aviation ministry said on Wednesday that the plane’s cockpit voice recorder had been partially damaged in the crash, potentially slowing the speed of the investigation.

“A lot of work is required in order to extract the data” from the recorder, which is one of the plane’s two “black boxes,” the ministry said in a statement. Investigators have safely obtained the contents of the aircraft’s flight data recorder, but have not yet analyzed the material, the ministry said.

Also Wednesday, the Islamic State affiliate released an audio clip reiterating the group’s claim to have brought down the airliner. The statement said the would soon announce how they did it.

“We are the ones who, through the grace of God, brought down the plane,” the statement said. “And [we] are not obliged to reveal the mechanics of this.”