One of the seven gunmen who killed 129 people in near-simultaneous attacks in Paris has been identified by French investigators, reports BBC.He was named as Omar Ismail Mostefai, a 29-year-old French citizen of Algerian origin, who had a criminal record and was known to have been radicalised.French prosecutors say the attacks were carried out by three coordinated teams of gunmen and suicide bombers.France has begun three days of national mourning. Some 350 people were injured.A special service for the families of the victims and survivors will be held at Paris`s Notre Dame Cathedral later on Sunday.Friday`s attacks, claimed by Islamic State (IS) militants, hit a concert hall, a major stadium, restaurants and bars in the French capital.Prime Minister Manuel Valls has said France will continue with air strikes against IS in Syria, and described the group as a very well-organised enemy.President Francois Hollande has cancelled his plans to attend the G20 in Turkey and is holding meetings with various political leaders to discuss the crisis.