Enver Alas / Istanbul, May 1 (DHA) - Istanbul’s iconic Taksim Square and surrounding districts, including Besiktas, are on lockdown by more than 20 thousand police officers and iron crush barriers to prevent celebrations of May Day. Authorities in Istanbul have tightened security ahead of the national holiday, with iron barricades erected in the city center. Taksim Square has symbolic meaning for the Turkish left, as over 30 people were killed in 1977 when suspected nationalists opened fire on May Day participants from what is now the Marmara Hotel. VIDEO STREAM ------------------- - D100 highway - Barbaros Boulevard intersection - Police blockades the traffic - People struggling on their way to offices - People talking police to open their way to offices - Bus station - Pedestrians - Beşiktaş traffic sign - Police checking identity cards - Police searching bags - Blocked-empty Barbaros Boulevard - TOMAs - Police officers - Pedestrians - General and detail views