ISTANBUL — A bomb rocked a bustling pedestrian avenue in the heart of Istanbul on Sunday, killing six people, wounding several dozen and leaving panicked people to flee the fiery blast or huddle in cafes and shops.Justice Minister Bekir Bozdag told pro-government broadcaster A Haber that investigators were focusing on a woman who sat on a bench by the scene of the blast for about 40 minutes.The manager, who spoke on condition of anonymity because of the sensitivity of the situation, said he closed his restaurant’s shutters, fearing there might be another explosion, and tried to calm the customers down.In another example of the country’s restrictions on the press, Turkey’s media watchdog also imposed temporary limits on reporting on Sunday’s explosion — a move that bans the use of close-up videos and photos of the blast and its aftermath.We stand at your side in the fight against terrorism.”___Associated Press journalists Cavit Ozgul and Khalil Hamra contributed to this report."