A U.S. Intelligence analysis has suggested the possibility of a bomb planted inside the Russian aeroplane, which crashed in Egypt with 224 passengers aboard on Saturday.

Earlier reports from authorities denied the claims of any Islamic State involvement in the matter, but the latest investigation suggested the IS militants’ engagement as an “external factor” that led to the crash of the Metrojet, or Kogalymavia, which took off from the resort of Sharm el-Sheikh.

The Russian airliner already claimed earlier that it was not a technical fault of the aeroplane, but some “external factor” that prompted to such a disastrous end of Metrojet Flight KGL9268. Though IS bomb attack seems to be a factor, no final conclusion has been made on the matter yet.

U.K. officials seconded the U.S. intelligence report. British Foreign Minister Philip Hammond said that even his government favoured the U.S. report and believed there is a “significant possibility” that an explosive caused the crash. “We have concluded that there is a significant possibility that the crash was caused by an explosive device on board the aircraft,” Hammond told reporters after the meeting of the government’s crisis response committee on Wednesday.

A source from the Middle East also said that it was likely that the bomb was planted inside the aeroplane ahead of its takeoff. Majority of its passengers were Russian.

One of the unnamed U.S. Intelligence officials, who was investigating the matter, told CNN that the bomb might have been planted in luggage or anywhere on the plane.

On the other hand, a Twitter audio message was posted by an IS’s Egyptian supporter, which said “we will disclose the mechanism of its demise at the time we want.”

Meanwhile, British aviation authorities have sent experts to Sharm el-Sheikh to assess the level of security being maintained. The flights that were about to take off from the resort have been put on halt till the security assessment is successfully completed later on Wednesday.

Contact the writer at feedback@ibtimes.com.au, or let us know what you think below.