MOSCOW, February 18 (RAPSI) – Investigation into the Airbus A321 plane crash in Egypt has been extended until April 30, 2016, RIA Novosti reported Thursday.

According to lawyer Igor Trunov, the case has been reclassified to terrorist attack and submitted to the Investigative Committee’s special cases directorate for inquiry.

The Airbus A321, operated by Russian airline Kogalymavia, crashed into a mountainous area of Egypt's Sinai Peninsula on October 31. The airliner was flying from the Red Sea resort of Sharm el-Sheikh to St Petersburg in Russia.

The Federal Security Service (FSB) chief, Alexander Bortnikov earlier said that a terrorist attack was the cause of the plane crash.

A militant group linked to Islamic State said in a statement that it had brought down the plane in response to Russian airstrikes in Syria.