CAIRO, Apr. 14 (Aswat Masriya) – Egypt's public prosecutor referred Thursday the investigation into the Russian airplane that crashed, killing all 224 people on board, last October in the Sinai Peninsula to the State Security prosecution.

This comes after the Egypt-led committee investigating the crash referred the case to Public Prosecutor Nabil Sadiq in mid-March after receiving a report from Russia suggesting suspected criminal activity.

The State Security prosecution is a branch of prosecution which is typically involved in cases that affect national security. 

In its statement Thursday, the public prosecution said the referral order means the case under investigation is within the jurisdiction of the State Security prosecution.

Russia and Western countries have long said that they believe the flight was brought down by a bomb smuggled on board.

However, the investigation has yet to find evidence supporting the claim that the plane was downed by a bomb.

The Islamic State-affiliate, Sinai Province, had claimed responsibility for the crash.

Egypt's president Abdel Fattah al-Sisi said in a speech in February that the plane was downed by terrorists seeking to damage its tourism industry and ties with Moscow.

Moscow suspended all flights to Egypt pending an investigation into the crash. The UK followed suit, halting all flights to and from Sharm el-Sheikh.

Russian President Vladimir Putin stated Thursday during his annual marathon question-and-answer session that flights to Egypt will not resume until Egypt and Russia agree on enhanced security checks. Such an agreement has yet to materialise, Putin added.

The crash has called into question Egypt's campaign to eradicate Islamist militancy and damaged its tourism industry, a cornerstone of the economy.