Russian plane crash Sinai
Debris from the Russian airplane is seen at its crash site at Hassana area in Arish cityMohamed Abd El Ghany/Reuters

Egyptian investigators have questioned Sharm el-Sheikh airport staff to determine whether any insiders were involved in planting bombs aboard the Russian passenger plane that killed 224 people on 31 October. The country's Ministry of Interior officials questioned airport workers to know where they were on the day of the crash.

Investigators, who earlier believed that the plane might have crashed due to a mechanical failure or pilot error, have now said that they were "90 per cent sure" that the aircraft was bombed with an explosion heard on the cockpit recorder right before it went silent. However, investigators have pointed out that there is no physical evidence as bomb fragments have not been discovered from the debris of the plane as yet.

The UK and the US have said that the most likely cause for the Russian plane crash was a terrorist attack and suggested that the local affiliate of Islamic State (Isis) in Sinai had carried out the bombing. Moreover, US officials said that the bomb may have been planted without the help of Isis leaders in Iraq and Syria.

Meanwhile, security has been beefed up at the Sharm el-Sheikh airport, where officers are guarding aircraft on the tarmac. "Normally, policemen are not allowed on the tarmac. Recently, they're being asked to spend nights beneath jets," a person familiar with the security arrangements told the Wall Street Journal. International airliners, who had temporarily suspended fights to Sinai, resumed operations over the weekend, (7-8 November).

Isis claim 'offshoot group' brought down plane

Isis's media wing from Aleppo released a new seven-minute video on Friday (^ November) reiterating its stance that an offshoot group of the terror organisation in Sinai province brought down the Russian passenger plane. In the video, titled "Healing Souls by Killing Russians", the terror group said its offshoot group had pledged their alliance to Abu Bakr al-Baghdadi a year ago.

The video goes on to state that the "Russian plane was brought down" because of the country's bombing campaign in Syria. However, details regarding how the plane might have been brought down are not mentioned in the video. "By God's will, and strong efforts of our brothers and soldiers on the ground in the province of Sinai, they brought down a Russian airplane, which carried over 220 Crusader Russians. All of them have been killed, and thanks to God for that," a narrator in the video said, as translated by Daily Mail.